diff --git a/Gruntfile.js b/Gruntfile.js
index 0295c3f..a35ade6 100644
--- a/Gruntfile.js
+++ b/Gruntfile.js
@@ -10,6 +10,14 @@ module.exports = function(grunt) {
         }]
       }
     },
+    copy: {
+      main: {
+        expand: true,
+        cwd: 'src',
+        src: 'locales/*',
+        dest: 'build'
+      }
+    },
     watch: {
       scripts: {
         files: ['src/**/*.js'],
@@ -20,6 +28,7 @@ module.exports = function(grunt) {
 
   grunt.loadNpmTasks('grunt-babel');
   grunt.loadNpmTasks('grunt-contrib-watch');
+  grunt.loadNpmTasks('grunt-contrib-copy');
 
   grunt.registerTask('default', ['babel']);
 };
diff --git a/README.es.md b/README.es.md
new file mode 100644
index 0000000..bc27d7a
--- /dev/null
+++ b/README.es.md
@@ -0,0 +1,34 @@
+node-games
+==========
+
+[English Version](README.md)
+
+Algunos juegos de consola escritos en Node.
+
+```
+npm i -g node-games
+
+node-games
+```
+
+Sin instalar el juego globalmente:
+```
+npm start <juego> <idioma>
+
+Ejemplo:
+npm start snake es
+
+(Si no se especifica el lenguage, por defecto se usa inglés)
+```
+
+spacecraft
+----------
+![spacecraft](spacecraft-es.gif)
+
+snake
+-----
+![snake](snake-es.gif)
+
+tanks
+-----
+![tanks](tanks-es.gif)
diff --git a/README.md b/README.md
index 34f75f0..f65d85c 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,8 @@
 node-games
 ==========
 
+[Version en español](README.es.md)
+
 Some fun console games written using Node.
 
 ```
@@ -9,6 +11,14 @@ npm i -g node-games
 node-games
 ```
 
+Without installing node-games globally:
+```
+npm start <game> <language>
+npm start snake es
+
+(English will be default language if none is given)
+```
+
 spacecraft
 ----------
 ![spacecraft](https://raw.githubusercontent.com/mdibaiee/node-games/master/spacecraft.gif)
diff --git a/build/classes/interface.js b/build/classes/interface.js
index 375b62e..9dbdb7a 100644
--- a/build/classes/interface.js
+++ b/build/classes/interface.js
@@ -1,11 +1,11 @@
 'use strict';
 
-var _createClass = (function () { function defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } } return function (Constructor, protoProps, staticProps) { if (protoProps) defineProperties(Constructor.prototype, protoProps); if (staticProps) defineProperties(Constructor, staticProps); return Constructor; }; })();
-
 Object.defineProperty(exports, "__esModule", {
   value: true
 });
 
+var _createClass = function () { function defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } } return function (Constructor, protoProps, staticProps) { if (protoProps) defineProperties(Constructor.prototype, protoProps); if (staticProps) defineProperties(Constructor, staticProps); return Constructor; }; }();
+
 var _ansi = require('ansi');
 
 var _ansi2 = _interopRequireDefault(_ansi);
@@ -14,28 +14,29 @@ function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { de
 
 function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
 
-var _process = process;
-var stdout = _process.stdout;
-var stdin = _process.stdin;
+var _process = process,
+    stdout = _process.stdout,
+    stdin = _process.stdin;
+
 
 var listeners = [];
 
-var prefix = '\u001b';
+var prefix = '\x1B';
 var keys = {
   right: prefix + '[C',
   up: prefix + '[A',
   left: prefix + '[D',
   down: prefix + '[B',
-  exit: '\u0003',
+  exit: '\x03',
   space: ' '
 };
 
-var Interface = (function () {
+var Interface = function () {
   function Interface() {
     var _this = this;
 
-    var output = arguments.length <= 0 || arguments[0] === undefined ? stdout : arguments[0];
-    var input = arguments.length <= 1 || arguments[1] === undefined ? stdin : arguments[1];
+    var output = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : stdout;
+    var input = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : stdin;
 
     _classCallCheck(this, Interface);
 
@@ -61,7 +62,7 @@ var Interface = (function () {
       });
 
       if (key === 'exit') {
-        _this.output.write('\u001b[2J\u001b[0;0H');
+        _this.output.write('\x1B[2J\x1B[0;0H');
         process.exit();
       }
 
@@ -78,7 +79,7 @@ var Interface = (function () {
   _createClass(Interface, [{
     key: 'clear',
     value: function clear() {
-      this.output.write('\u001b[2J\u001b[0;0H');
+      this.output.write('\x1B[2J\x1B[0;0H');
     }
   }, {
     key: 'write',
@@ -110,6 +111,7 @@ var Interface = (function () {
 
       var y = from.y;
 
+
       for (var x = from.x; x < to.x; x++) {
         this.cursor.goto(x, y);
         this.write('.');
@@ -145,6 +147,6 @@ var Interface = (function () {
   }]);
 
   return Interface;
-})();
+}();
 
 exports.default = Interface;
diff --git a/build/classes/log b/build/classes/log
deleted file mode 100644
index ae06f0c..0000000
--- a/build/classes/log
+++ /dev/null
@@ -1,5 +0,0 @@
-0(0) = 0,1
-45(0.7853981633974483) = 0.7071067811865475,0.7071067811865476
-112.5(1.9634954084936207) = 0.9238795325112867,-0.3826834323650897
-157.5(2.748893571891069) = 0.3826834323650899,-0.9238795325112867
-180(3.141592653589793) = 1.2246467991473532e-16,-1
diff --git a/build/classes/tank.js b/build/classes/tank.js
index 6ff327d..9a7e3c9 100644
--- a/build/classes/tank.js
+++ b/build/classes/tank.js
@@ -1,12 +1,12 @@
 'use strict';
 
-var _createClass = (function () { function defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } } return function (Constructor, protoProps, staticProps) { if (protoProps) defineProperties(Constructor.prototype, protoProps); if (staticProps) defineProperties(Constructor, staticProps); return Constructor; }; })();
-
 Object.defineProperty(exports, "__esModule", {
   value: true
 });
 exports.Bullet = undefined;
 
+var _createClass = function () { function defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } } return function (Constructor, protoProps, staticProps) { if (protoProps) defineProperties(Constructor.prototype, protoProps); if (staticProps) defineProperties(Constructor, staticProps); return Constructor; }; }();
+
 var _unit = require('./unit');
 
 var _unit2 = _interopRequireDefault(_unit);
@@ -21,13 +21,13 @@ function _inherits(subClass, superClass) { if (typeof superClass !== "function"
 
 var BULLET_SPEED = 10;
 
-var Tank = (function (_Unit) {
+var Tank = function (_Unit) {
   _inherits(Tank, _Unit);
 
   function Tank(ui) {
     _classCallCheck(this, Tank);
 
-    var _this = _possibleConstructorReturn(this, Object.getPrototypeOf(Tank).call(this, ui));
+    var _this = _possibleConstructorReturn(this, (Tank.__proto__ || Object.getPrototypeOf(Tank)).call(this, ui));
 
     _this._angle = 0;
     _this.bullets = [];
@@ -51,8 +51,8 @@ var Tank = (function (_Unit) {
     value: function draw() {
       if (this.dead) return;
 
-      var x = this.x;
-      var y = this.y;
+      var x = this.x,
+          y = this.y;
 
       if (this.color && this.color[0] === '#') {
         this.output.cursor.hex(this.color);
@@ -64,7 +64,7 @@ var Tank = (function (_Unit) {
       x = Math.round(x) + 2;
       y = Math.round(y) - 2;
 
-      var cannon = undefined;
+      var cannon = void 0;
       if (this.angle < 35) cannon = '_';else if (this.angle < 70) cannon = '/';else if (this.angle < 115) cannon = '|';else if (this.angle < 160) cannon = '\\';else cannon = '_';
 
       this.output.cursor.goto(x + 2, y - 2);
@@ -104,17 +104,17 @@ var Tank = (function (_Unit) {
   }]);
 
   return Tank;
-})(_unit2.default);
+}(_unit2.default);
 
 exports.default = Tank;
 
-var Bullet = exports.Bullet = (function (_Unit2) {
+var Bullet = exports.Bullet = function (_Unit2) {
   _inherits(Bullet, _Unit2);
 
   function Bullet(ui) {
     _classCallCheck(this, Bullet);
 
-    var _this2 = _possibleConstructorReturn(this, Object.getPrototypeOf(Bullet).call(this, ui));
+    var _this2 = _possibleConstructorReturn(this, (Bullet.__proto__ || Object.getPrototypeOf(Bullet)).call(this, ui));
 
     _this2.velocity = [0, 0];
 
@@ -151,7 +151,7 @@ var Bullet = exports.Bullet = (function (_Unit2) {
   }]);
 
   return Bullet;
-})(_unit2.default);
+}(_unit2.default);
 
 function _radian(deg) {
   return deg * Math.PI / 180;
diff --git a/build/classes/unit.js b/build/classes/unit.js
index 2728e25..a72f4bc 100644
--- a/build/classes/unit.js
+++ b/build/classes/unit.js
@@ -1,16 +1,16 @@
 'use strict';
 
-var _createClass = (function () { function defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } } return function (Constructor, protoProps, staticProps) { if (protoProps) defineProperties(Constructor.prototype, protoProps); if (staticProps) defineProperties(Constructor, staticProps); return Constructor; }; })();
-
 Object.defineProperty(exports, "__esModule", {
   value: true
 });
 
+var _createClass = function () { function defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } } return function (Constructor, protoProps, staticProps) { if (protoProps) defineProperties(Constructor.prototype, protoProps); if (staticProps) defineProperties(Constructor, staticProps); return Constructor; }; }();
+
 function _toConsumableArray(arr) { if (Array.isArray(arr)) { for (var i = 0, arr2 = Array(arr.length); i < arr.length; i++) { arr2[i] = arr[i]; } return arr2; } else { return Array.from(arr); } }
 
 function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
 
-var Unit = (function () {
+var Unit = function () {
   function Unit(output) {
     _classCallCheck(this, Unit);
 
@@ -33,9 +33,9 @@ var Unit = (function () {
     value: function draw() {
       if (this.dead) return;
 
-      var x = this.x;
-      var y = this.y;
-      var shape = this.shape;
+      var x = this.x,
+          y = this.y,
+          shape = this.shape;
 
       if (this.color && this.color[0] === '#') {
         this.output.cursor.hex(this.color);
@@ -123,6 +123,6 @@ var Unit = (function () {
   }]);
 
   return Unit;
-})();
+}();
 
 exports.default = Unit;
diff --git a/build/locales/en.json b/build/locales/en.json
new file mode 100644
index 0000000..f3be16f
--- /dev/null
+++ b/build/locales/en.json
@@ -0,0 +1,17 @@
+{
+  "snake": {
+    "score": "Score",
+    "gameOver": "Game Over!",
+    "anyKey": "Press any key to play again"
+  },
+  "tanks": {
+    "playerWon": "Player %{num} won!",
+    "player": "Player %{number}",
+    "health": "Health %{value}",
+    "angle": "Angle %{value}"
+  },
+  "spacecraft": {
+    "score": "Score"
+  }
+}
+
diff --git a/build/locales/es.json b/build/locales/es.json
new file mode 100644
index 0000000..04d9a79
--- /dev/null
+++ b/build/locales/es.json
@@ -0,0 +1,16 @@
+{
+  "snake": {
+    "score": "Puntaje",
+    "gameOver": "¡Se acabó el juego!",
+    "anyKey": "Presioná cualquier tecla para jugar nuevamente"
+  },
+  "tanks": {
+    "playerWon": "¡Ha ganado el jugador %{name}!",
+    "player": "Jugador %{number}",
+    "health": "Salud %{value}",
+    "angle": "Ángulo %{value}"
+  },
+  "spacecraft": {
+    "score": "Puntaje"
+  }
+}
diff --git a/build/log b/build/log
deleted file mode 100644
index 3a9143c..0000000
--- a/build/log
+++ /dev/null
@@ -1,174 +0,0 @@
-0 (0) =  0,1
-45 (0.7853981633974483) =  0.7071067811865475,0.7071067811865476
-45 (0.7853981633974483) =  0.7071067811865475,0.7071067811865476
-90 (1.5707963267948966) =  1,6.123233995736766e-17
-135 (2.356194490192345) =  0.7071067811865476,-0.7071067811865475
-180 (3.141592653589793) =  1.2246467991473532e-16,-1
-0 (0) = 1,0
-45 (0.7853981633974483) = 0.7071067811865476,0.7071067811865475
-90 (1.5707963267948966) = 6.123233995736766e-17,1
-135 (2.356194490192345) = -0.7071067811865475,0.7071067811865476
-180 (3.141592653589793) = -1,1.2246467991473532e-16
-0 (0) = -1,0
-45 (0.7853981633974483) = -0.7071067811865476,-0.7071067811865475
-90 (1.5707963267948966) = -6.123233995736766e-17,-1
-0 (0) = 1,0
-45 (0.7853981633974483) = 0.7071067811865476,-0.7071067811865475
-90 (1.5707963267948966) = 6.123233995736766e-17,-1
-135 (2.356194490192345) = -0.7071067811865475,-0.7071067811865476
-180 (3.141592653589793) = -1,-1.2246467991473532e-16
-0 (0) = 1,0
-45 (0.7853981633974483) = 0.7071067811865476,-0.7071067811865475
-90 (1.5707963267948966) = 6.123233995736766e-17,-1
-135 (2.356194490192345) = -0.7071067811865475,-0.7071067811865476
-180 (3.141592653589793) = -1,-1.2246467991473532e-16
-112.5 (1.9634954084936207) = -0.3826834323650897,-0.9238795325112867
-112.5 (1.9634954084936207) = -0.3826834323650897,-0.9238795325112867
-112.5 (1.9634954084936207) = -0.3826834323650897,-0.9238795325112867
-90 (1.5707963267948966) = 6.123233995736766e-17,-1
-45 (0.7853981633974483) = 0.7071067811865476,-0.7071067811865475
-45 (0.7853981633974483) = 0.7071067811865476,-0.7071067811865475
-45 (0.7853981633974483) = 0.7071067811865476,-0.7071067811865475
-45 (0.7853981633974483) = 0.7071067811865476,-0.7071067811865475
-45 (0.7853981633974483) = 0.7071067811865476,-0.7071067811865475
-45 (0.7853981633974483) = 0.7071067811865476,-0.7071067811865475
-45 (0.7853981633974483) = 0.7071067811865476,-0.7071067811865475
-45 (0.7853981633974483) = 0.7071067811865476,-0.7071067811865475
-45 (0.7853981633974483) = 0.7071067811865476,-0.7071067811865475
-45 (0.7853981633974483) = 0.7071067811865476,-0.7071067811865475
-45 (0.7853981633974483) = 0.7071067811865476,-0.7071067811865475
-45 (0.7853981633974483) = 0.7071067811865476,-0.7071067811865475
-45 (0.7853981633974483) = 0.7071067811865476,-0.7071067811865475
-22.5 (0.39269908169872414) = 0.9238795325112867,-0.3826834323650898
-22.5 (0.39269908169872414) = 0.9238795325112867,-0.3826834323650898
-45 (0.7853981633974483) = 0.7071067811865476,-0.7071067811865475
-0 (0) = 1,0
-22.5 (0.39269908169872414) = 0.9238795325112867,-0.3826834323650898
-53.999999999999964 (0.9424777960769373) = 0.5877852522924737,-0.809016994374947
-0 (0) = 1,0
-54.999999999999964 (0.9599310885968807) = 0.5735764363510466,-0.8191520442889915
-180 (3.141592653589793) = -1,-1.2246467991473532e-16
-32.99999999999997 (0.5759586531581282) = 0.8386705679454243,-0.5446390350150266
-170.00000000000003 (2.967059728390361) = -0.9848077530122081,-0.17364817766692983
-42.99999999999997 (0.7504915783575612) = 0.7313537016191709,-0.6819983600624981
-170.00000000000003 (2.967059728390361) = -0.9848077530122081,-0.17364817766692983
-42.99999999999997 (0.7504915783575612) = 0.7313537016191709,-0.6819983600624981
-170.00000000000003 (2.967059728390361) = -0.9848077530122081,-0.17364817766692983
-45.99999999999997 (0.802851455917391) = 0.6946583704589977,-0.7193398003386507
-170.00000000000003 (2.967059728390361) = -0.9848077530122081,-0.17364817766692983
-35 (0.6108652381980153) = 0.8191520442889918,-0.573576436351046
-49.99999999999997 (0.8726646259971643) = 0.6427876096865397,-0.7660444431189777
-162.00000000000009 (2.827433388230815) = -0.951056516295154,-0.3090169943749463
-48.99999999999997 (0.8552113334772209) = 0.6560590289905077,-0.7547095802227716
-167.00000000000009 (2.914699850830532) = -0.9743700647852356,-0.22495105434386348
-46.999999999999964 (0.8203047484373343) = 0.6819983600624989,-0.73135370161917
-48.99999999999997 (0.8552113334772209) = 0.6560590289905077,-0.7547095802227716
-45.999999999999986 (0.8028514559173914) = 0.6946583704589975,-0.7193398003386511
-162.00000000000009 (2.827433388230815) = -0.951056516295154,-0.3090169943749463
-45.999999999999986 (0.8028514559173914) = 0.6946583704589975,-0.7193398003386511
-162.00000000000009 (2.827433388230815) = -0.951056516295154,-0.3090169943749463
-45.999999999999986 (0.8028514559173914) = 0.6946583704589975,-0.7193398003386511
-162.00000000000009 (2.827433388230815) = -0.951056516295154,-0.3090169943749463
-45.999999999999986 (0.8028514559173914) = 0.6946583704589975,-0.7193398003386511
-162.00000000000009 (2.827433388230815) = -0.951056516295154,-0.3090169943749463
-45.999999999999986 (0.8028514559173914) = 0.6946583704589975,-0.7193398003386511
-162.00000000000009 (2.827433388230815) = -0.951056516295154,-0.3090169943749463
-45.999999999999986 (0.8028514559173914) = 0.6946583704589975,-0.7193398003386511
-162.00000000000009 (2.827433388230815) = -0.951056516295154,-0.3090169943749463
-45.999999999999986 (0.8028514559173914) = 0.6946583704589975,-0.7193398003386511
-162.00000000000009 (2.827433388230815) = -0.951056516295154,-0.3090169943749463
-45.999999999999986 (0.8028514559173914) = 0.6946583704589975,-0.7193398003386511
-162.00000000000009 (2.827433388230815) = -0.951056516295154,-0.3090169943749463
-45.999999999999986 (0.8028514559173914) = 0.6946583704589975,-0.7193398003386511
-162.00000000000009 (2.827433388230815) = -0.951056516295154,-0.3090169943749463
-20.999999999999986 (0.366519142918809) = 0.9335804264972019,-0.35836794954530005
-46.999999999999986 (0.8203047484373346) = 0.6819983600624987,-0.7313537016191702
-147 (2.5656340004316647) = -0.8386705679454242,-0.5446390350150269
-26.999999999999993 (0.47123889803846886) = 0.8910065241883679,-0.4539904997395467
-147 (2.5656340004316647) = -0.8386705679454242,-0.5446390350150269
-10.99999999999999 (0.19198621771937607) = 0.981627183447664,-0.19080899537654464
-147 (2.5656340004316647) = -0.8386705679454242,-0.5446390350150269
-10.99999999999999 (0.19198621771937607) = 0.981627183447664,-0.19080899537654464
-147 (2.5656340004316647) = -0.8386705679454242,-0.5446390350150269
-10.99999999999999 (0.19198621771937607) = 0.981627183447664,-0.19080899537654464
-147 (2.5656340004316647) = -0.8386705679454242,-0.5446390350150269
-10.99999999999999 (0.19198621771937607) = 0.981627183447664,-0.19080899537654464
-147 (2.5656340004316647) = -0.8386705679454242,-0.5446390350150269
-10.99999999999999 (0.19198621771937607) = 0.981627183447664,-0.19080899537654464
-147 (2.5656340004316647) = -0.8386705679454242,-0.5446390350150269
-10.99999999999999 (0.19198621771937607) = 0.981627183447664,-0.19080899537654464
-147 (2.5656340004316647) = -0.8386705679454242,-0.5446390350150269
-10.99999999999999 (0.19198621771937607) = 0.981627183447664,-0.19080899537654464
-147 (2.5656340004316647) = -0.8386705679454242,-0.5446390350150269
-10.99999999999999 (0.19198621771937607) = 0.981627183447664,-0.19080899537654464
-147 (2.5656340004316647) = -0.8386705679454242,-0.5446390350150269
-10.99999999999999 (0.19198621771937607) = 0.981627183447664,-0.19080899537654464
-48.99999999999998 (0.8552113334772211) = 0.6560590289905076,-0.7547095802227717
-10 (0.17453292519943295) = 0.984807753012208,-0.17364817766693033
-0 (0) = 1,0
-10 (0.17453292519943295) = 0.984807753012208,-0.17364817766693033
-0 (0) = 1,0
-10 (0.17453292519943295) = 0.984807753012208,-0.17364817766693033
-0 (0) = 1,0
-10 (0.17453292519943295) = 0.984807753012208,-0.17364817766693033
-0 (0) = 1,0
-10 (0.17453292519943295) = 0.984807753012208,-0.17364817766693033
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-49.99999999999997 (0.8726646259971643) = 0.6427876096865397,-0.7660444431189777
-19.999999999999986 (0.3490658503988657) = 0.9396926207859084,-0.3420201433256685
-0 (0) = 1,0
-19.999999999999986 (0.3490658503988657) = 0.9396926207859084,-0.3420201433256685
-0 (0) = 1,0
-19.999999999999986 (0.3490658503988657) = 0.9396926207859084,-0.3420201433256685
-0 (0) = 1,0
-0 (0) = 1,0
-0 (0) = 1,0
-180 (3.141592653589793) = -1,-1.2246467991473532e-16
-180 (3.141592653589793) = -1,-1.2246467991473532e-16
-180 (3.141592653589793) = -1,-1.2246467991473532e-16
-180 (3.141592653589793) = -1,-1.2246467991473532e-16
-180 (3.141592653589793) = -1,-1.2246467991473532e-16
-180 (3.141592653589793) = -1,-1.2246467991473532e-16
-0 (0) = 1,0
-0 (0) = 1,0
-47.99999999999998 (0.8377580409572778) = 0.6691306063588585,-0.743144825477394
-134.99999999999991 (2.3561944901923435) = -0.7071067811865466,-0.7071067811865486
diff --git a/build/snake.js b/build/snake.js
index 4677856..f0f119c 100644
--- a/build/snake.js
+++ b/build/snake.js
@@ -1,6 +1,31 @@
 'use strict';
 
-var _slicedToArray = (function () { function sliceIterator(arr, i) { var _arr = []; var _n = true; var _d = false; var _e = undefined; try { for (var _i = arr[Symbol.iterator](), _s; !(_n = (_s = _i.next()).done); _n = true) { _arr.push(_s.value); if (i && _arr.length === i) break; } } catch (err) { _d = true; _e = err; } finally { try { if (!_n && _i["return"]) _i["return"](); } finally { if (_d) throw _e; } } return _arr; } return function (arr, i) { if (Array.isArray(arr)) { return arr; } else if (Symbol.iterator in Object(arr)) { return sliceIterator(arr, i); } else { throw new TypeError("Invalid attempt to destructure non-iterable instance"); } }; })();
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+
+var _slicedToArray = function () { function sliceIterator(arr, i) { var _arr = []; var _n = true; var _d = false; var _e = undefined; try { for (var _i = arr[Symbol.iterator](), _s; !(_n = (_s = _i.next()).done); _n = true) { _arr.push(_s.value); if (i && _arr.length === i) break; } } catch (err) { _d = true; _e = err; } finally { try { if (!_n && _i["return"]) _i["return"](); } finally { if (_d) throw _e; } } return _arr; } return function (arr, i) { if (Array.isArray(arr)) { return arr; } else if (Symbol.iterator in Object(arr)) { return sliceIterator(arr, i); } else { throw new TypeError("Invalid attempt to destructure non-iterable instance"); } }; }();
+
+exports.default = function (i18n) {
+  loop(i18n);
+
+  ui.onKey(function () {
+    if (!stop) return;
+
+    stop = false;
+    snake = [];
+    head = createPart();
+    head.color = '#71da29';
+    createPart();
+    createPart();
+
+    score = 0;
+
+    point.random();
+
+    loop(i18n);
+  });
+};
 
 var _unit = require('./classes/unit');
 
@@ -34,7 +59,7 @@ point.random();
 var score = 0;
 
 var stop = false;
-function loop() {
+function loop(i18n) {
   if (stop) return;
   ui.clear();
 
@@ -57,17 +82,15 @@ function loop() {
   }
 
   if (head.collides(snake.slice(2))) {
-    gameover();
+    gameover(i18n);
   }
 
-  ui.cursor.goto(0, 0).yellow().write('Score: ' + score);
+  ui.cursor.goto(0, 0).yellow().write(i18n.t('snake.score') + ': ' + score);
   ui.cursor.reset();
 
-  setTimeout(loop, FRAME);
+  setTimeout(loop, FRAME, i18n);
 }
 
-loop();
-
 ui.onKey('right', function () {
   changeDirection(RIGHT);
 });
@@ -81,23 +104,6 @@ ui.onKey('left', function () {
   changeDirection(LEFT);
 });
 
-ui.onKey(function () {
-  if (!stop) return;
-
-  stop = false;
-  snake = [];
-  head = createPart();
-  head.color = '#71da29';
-  createPart();
-  createPart();
-
-  score = 0;
-
-  point.random();
-
-  loop();
-});
-
 function changeDirection(dir) {
   if (head.direction === UP && dir === DOWN || head.direction === DOWN && dir === UP || head.direction === LEFT && dir === RIGHT || head.direction === RIGHT && dir === LEFT) return;
   head.direction = dir;
@@ -107,7 +113,7 @@ function createPart() {
   var part = new _unit2.default(ui);
   var last = snake[snake.length - 1];
 
-  var direction = undefined;
+  var direction = void 0;
   if (!last) {
     direction = UP;
   } else {
@@ -132,21 +138,19 @@ function createPart() {
   };
 
   part.speed = function () {
-    var multiplier = arguments.length <= 0 || arguments[0] === undefined ? 1 : arguments[0];
+    var multiplier = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : 1;
     var direction = part.direction;
 
-    var x = direction == LEFT ? -1 : direction == RIGHT ? 1 : 0;
-    var y = direction == UP ? -1 : direction == DOWN ? 1 : 0;
+    var x = direction === LEFT ? -1 : direction === RIGHT ? 1 : 0;
+    var y = direction === UP ? -1 : direction === DOWN ? 1 : 0;
 
     return [x * multiplier, y * multiplier];
   };
 
-  var _part$speed = part.speed();
-
-  var _part$speed2 = _slicedToArray(_part$speed, 2);
-
-  var dX = _part$speed2[0];
-  var dY = _part$speed2[1];
+  var _part$speed = part.speed(),
+      _part$speed2 = _slicedToArray(_part$speed, 2),
+      dX = _part$speed2[0],
+      dY = _part$speed2[1];
 
   dX *= -1;
   dY *= -1;
@@ -160,8 +164,8 @@ function createPart() {
   return part;
 }
 
-function gameover() {
-  var MSG = 'Game Over!';
+function gameover(i18n) {
+  var MSG = i18n.t('snake.gameOver');
   ui.cursor.goto(ui.center.x - MSG.length / 2, ui.center.y);
   ui.cursor.red();
   ui.cursor.bold();
@@ -169,7 +173,7 @@ function gameover() {
 
   ui.cursor.reset();
   ui.cursor.hex('#f65590');
-  var RETRY = 'Press any key to play again';
+  var RETRY = i18n.t('snake.anyKey');
   ui.cursor.goto(ui.center.x - RETRY.length / 2, ui.center.y + 2);
   ui.write(RETRY);
 
diff --git a/build/spacecraft.js b/build/spacecraft.js
index 02315a2..fdad993 100644
--- a/build/spacecraft.js
+++ b/build/spacecraft.js
@@ -1,5 +1,54 @@
 'use strict';
 
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+
+exports.default = function (i18n) {
+  setInterval(function (i18n) {
+    ui.clear();
+
+    player.draw();
+
+    missles.forEach(function (missle, i) {
+      missle.move(1, 0);
+      missle.draw();
+
+      var enemy = missle.collides(enemies);
+      if (enemy) {
+        enemy.killed = 1;
+        enemy.color = 'red';
+        enemy.shape = '*';
+        missle.dead = true;
+
+        ENEMY_SPAWN_RATE -= 5;
+
+        score++;
+      }
+
+      if (missle.dead) {
+        missles.splice(i, 1);
+      }
+    });
+
+    enemies.forEach(function (enemy, i) {
+      // move with speed
+      enemy.move();
+      enemy.draw();
+
+      if (enemy.dead) {
+        enemies.splice(i, 1);
+      }
+
+      if (enemy.killed === 3) enemy.dead = true;
+      if (enemy.killed < 3) enemy.killed++;
+    });
+
+    ui.cursor.goto(0, 0).yellow().write(i18n.t('spacecraft.score') + ': ' + score);
+    ui.cursor.reset();
+  }, FRAME, i18n);
+};
+
 var _unit = require('./classes/unit');
 
 var _unit2 = _interopRequireDefault(_unit);
@@ -29,48 +78,6 @@ explosion.dead = true;
 var missles = [];
 var enemies = [];
 var score = 0;
-setInterval(function () {
-  ui.clear();
-
-  player.draw();
-
-  missles.forEach(function (missle, i) {
-    missle.move(1, 0);
-    missle.draw();
-
-    var enemy = missle.collides(enemies);
-    if (enemy) {
-      enemy.killed = 1;
-      enemy.color = 'red';
-      enemy.shape = '*';
-      missle.dead = true;
-
-      ENEMY_SPAWN_RATE -= 5;
-
-      score++;
-    }
-
-    if (missle.dead) {
-      missles.splice(i, 1);
-    }
-  });
-
-  enemies.forEach(function (enemy, i) {
-    // move with speed
-    enemy.move();
-    enemy.draw();
-
-    if (enemy.dead) {
-      enemies.splice(i, 1);
-    }
-
-    if (enemy.killed == 3) enemy.dead = true;
-    if (enemy.killed < 3) enemy.killed++;
-  });
-
-  ui.cursor.goto(0, 0).yellow().write('Score: ' + score);
-  ui.cursor.reset();
-}, FRAME);
 
 ui.onKey('right', function () {
   player.move(1, 0);
diff --git a/build/tanks.js b/build/tanks.js
index 6eb279e..e19a3a5 100644
--- a/build/tanks.js
+++ b/build/tanks.js
@@ -1,8 +1,12 @@
 'use strict';
 
-var _unit = require('./classes/unit');
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
 
-var _unit2 = _interopRequireDefault(_unit);
+exports.default = function (i18n) {
+  loop(i18n);
+};
 
 var _tank = require('./classes/tank');
 
@@ -26,14 +30,14 @@ two.go(ui.columns - 10, ui.rows);
 
 var stop = false;
 
-function loop() {
+function loop(i18n) {
   if (stop) return;
 
   ui.clear();
 
   if (one.dead || two.dead) {
     var num = one.dead ? '2' : '1';
-    var msg = 'Player ' + num + ' won!';
+    var msg = i18n.t('tanks.playerWon', { num: num });
     ui.cursor.red();
     ui.cursor.bold();
 
@@ -62,12 +66,12 @@ function loop() {
 
   ui.cursor.goto(0, 1);
   if (turn() === one) ui.cursor.hex('#54ffff');
-  ui.write('Player 1');
+  ui.write(i18n.t('tanks.player', { number: "1" }));
   ui.cursor.reset();
   ui.cursor.goto(0, 2);
-  ui.write('Health: ' + one.health);
+  ui.write(i18n.t('tanks.health', { value: one.health }));
   ui.cursor.goto(0, 3);
-  ui.write('Angle: ' + parseInt(one.angle));
+  ui.write(i18n.t('tanks.angle', { value: parseInt(one.angle) }));
 
   two.draw();
   two.bullets.forEach(function (bullet, i) {
@@ -87,18 +91,16 @@ function loop() {
 
   ui.cursor.goto(ui.output.columns - 10, 1);
   if (turn() === two) ui.cursor.hex('#54ffff');
-  ui.write('Player 2');
+  ui.write(i18n.t('tanks.player', { number: "2" }));
   ui.cursor.reset();
   ui.cursor.goto(ui.output.columns - 10, 2);
-  ui.write('Health: ' + two.health);
+  ui.write(i18n.t('tanks.health', { value: two.health }));
   ui.cursor.goto(ui.output.columns - 10, 3);
-  ui.write('Angle: ' + parseInt(two.angle));
+  ui.write(i18n.t('tanks.angle', { value: parseInt(two.angle) }));
 
-  setTimeout(loop, FRAME);
+  setTimeout(loop, FRAME, i18n);
 }
 
-loop();
-
 ui.onKey('down', function () {
   if (immoblize) return;
 
diff --git a/index.js b/index.js
index 5ef109d..8c57fd8 100755
--- a/index.js
+++ b/index.js
@@ -1,6 +1,7 @@
 #!/usr/bin/env node
 
 var game = process.argv[2];
+var language = process.argv[3];
 
 if (!game) {
   console.log('usage: node-games <game>');
@@ -14,4 +15,11 @@ if (!game) {
 
 require('babel-polyfill');
 
-require(__dirname + '/build/' + game);
+const gameToPlay = require(__dirname + '/build/' + game).default;
+
+const locale = require(`${__dirname}/locales/${language || 'en'}.json`);
+const Polyglot = require('node-polyglot');
+const i18n = new Polyglot({phrases: locale});
+
+gameToPlay(i18n);
+
diff --git a/locales/en.json b/locales/en.json
new file mode 100644
index 0000000..f3be16f
--- /dev/null
+++ b/locales/en.json
@@ -0,0 +1,17 @@
+{
+  "snake": {
+    "score": "Score",
+    "gameOver": "Game Over!",
+    "anyKey": "Press any key to play again"
+  },
+  "tanks": {
+    "playerWon": "Player %{num} won!",
+    "player": "Player %{number}",
+    "health": "Health %{value}",
+    "angle": "Angle %{value}"
+  },
+  "spacecraft": {
+    "score": "Score"
+  }
+}
+
diff --git a/locales/es.json b/locales/es.json
new file mode 100644
index 0000000..04d9a79
--- /dev/null
+++ b/locales/es.json
@@ -0,0 +1,16 @@
+{
+  "snake": {
+    "score": "Puntaje",
+    "gameOver": "¡Se acabó el juego!",
+    "anyKey": "Presioná cualquier tecla para jugar nuevamente"
+  },
+  "tanks": {
+    "playerWon": "¡Ha ganado el jugador %{name}!",
+    "player": "Jugador %{number}",
+    "health": "Salud %{value}",
+    "angle": "Ángulo %{value}"
+  },
+  "spacecraft": {
+    "score": "Puntaje"
+  }
+}
diff --git a/package.json b/package.json
index 1310f24..92086d3 100644
--- a/package.json
+++ b/package.json
@@ -4,6 +4,8 @@
   "description": "Simple node console games",
   "main": "index.js",
   "scripts": {
+    "build": "grunt && grunt copy",
+    "start": "node index.js",
     "test": "echo \"Error: no test specified\" && exit 1"
   },
   "bin": "index.js",
@@ -23,13 +25,16 @@
   "homepage": "https://github.com/mdibaiee/node-games#readme",
   "dependencies": {
     "ansi": "0.3.0",
-    "babel-core": "6.3.17",
+    "babel-core": "^6.26.3",
     "babel-polyfill": "6.3.14",
-    "babel-preset-es2015": "6.3.13"
+    "babel-preset-es2015": "6.3.13",
+    "node-polyglot": "^2.3.0"
   },
   "devDependencies": {
     "grunt": "0.4.5",
     "grunt-babel": "6.0.0",
+    "grunt-cli": "^1.3.2",
+    "grunt-contrib-copy": "^1.0.0",
     "grunt-contrib-watch": "0.6.1"
   }
 }
diff --git a/snake-es.gif b/snake-es.gif
new file mode 100644
index 0000000..7d9c723
Binary files /dev/null and b/snake-es.gif differ
diff --git a/spacecraft-es.gif b/spacecraft-es.gif
new file mode 100644
index 0000000..3d1ce7e
Binary files /dev/null and b/spacecraft-es.gif differ
diff --git a/src/snake.js b/src/snake.js
index 94f48c8..2356e7e 100644
--- a/src/snake.js
+++ b/src/snake.js
@@ -23,7 +23,7 @@ point.random();
 let score = 0;
 
 let stop = false;
-function loop() {
+function loop(i18n) {
   if (stop) return;
   ui.clear();
 
@@ -46,17 +46,15 @@ function loop() {
   }
 
   if (head.collides(snake.slice(2))) {
-    gameover();
+    gameover(i18n);
   }
 
-  ui.cursor.goto(0, 0).yellow().write(`Score: ${score}`);
+  ui.cursor.goto(0, 0).yellow().write(`${i18n.t('snake.score')}: ${score}`);
   ui.cursor.reset();
 
-  setTimeout(loop, FRAME);
+  setTimeout(loop, FRAME, i18n);
 }
 
-loop();
-
 ui.onKey('right', () => {
   changeDirection(RIGHT);
 });
@@ -70,23 +68,6 @@ ui.onKey('left', () => {
   changeDirection(LEFT);
 });
 
-ui.onKey(() => {
-  if (!stop) return;
-
-  stop = false;
-  snake = [];
-  head = createPart();
-  head.color = '#71da29';
-  createPart();
-  createPart();
-
-  score = 0;
-
-  point.random();
-
-  loop();
-})
-
 function changeDirection(dir) {
   if (head.direction === UP && dir === DOWN ||
       head.direction === DOWN && dir === UP ||
@@ -121,17 +102,17 @@ function createPart() {
     if (this.direction !== ahead.direction) {
       this.changeTo = ahead.direction;
     }
-  }
+  };
 
   part.speed = function(multiplier = 1) {
     let { direction } = part;
-    let x = direction == LEFT ? -1 :
-            direction == RIGHT ? 1 : 0;
-    let y = direction == UP ? -1 :
-            direction == DOWN ? 1 : 0;
+    let x = direction === LEFT ? -1 :
+            direction === RIGHT ? 1 : 0;
+    let y = direction === UP ? -1 :
+            direction === DOWN ? 1 : 0;
 
     return [x * multiplier, y * multiplier];
-  }
+  };
 
   let [dX, dY] = part.speed();
   dX *= -1;
@@ -146,8 +127,8 @@ function createPart() {
   return part;
 }
 
-function gameover() {
-  const MSG = 'Game Over!';
+function gameover(i18n) {
+  const MSG = i18n.t('snake.gameOver');
   ui.cursor.goto(ui.center.x - MSG.length / 2, ui.center.y);
   ui.cursor.red();
   ui.cursor.bold();
@@ -155,7 +136,7 @@ function gameover() {
 
   ui.cursor.reset();
   ui.cursor.hex('#f65590');
-  const RETRY = 'Press any key to play again';
+  const RETRY = i18n.t('snake.anyKey');
   ui.cursor.goto(ui.center.x - RETRY.length / 2, ui.center.y + 2);
   ui.write(RETRY);
 
@@ -165,6 +146,27 @@ function gameover() {
 }
 
 process.on('exit', function() {
-  ui.cursor.horizontalAbsolute(0).eraseLine()
+  ui.cursor.horizontalAbsolute(0).eraseLine();
   ui.cursor.show();
 });
+
+export default function(i18n) {
+  loop(i18n);
+
+  ui.onKey(() => {
+    if (!stop) return;
+
+    stop = false;
+    snake = [];
+    head = createPart();
+    head.color = '#71da29';
+    createPart();
+    createPart();
+
+    score = 0;
+
+    point.random();
+
+    loop(i18n);
+  });
+}
diff --git a/src/spacecraft.js b/src/spacecraft.js
index 17203fa..7ee812f 100644
--- a/src/spacecraft.js
+++ b/src/spacecraft.js
@@ -20,49 +20,51 @@ explosion.dead = true;
 let missles = [];
 let enemies = [];
 let score = 0;
-setInterval(() => {
-  ui.clear();
 
-  player.draw();
+export default function(i18n) {
+  setInterval((i18n) => {
+    ui.clear();
 
-  missles.forEach((missle, i) => {
-    missle.move(1, 0);
-    missle.draw();
+    player.draw();
 
-    let enemy = missle.collides(enemies)
-    if (enemy) {
-      enemy.killed = 1;
-      enemy.color = 'red';
-      enemy.shape = '*';
-      missle.dead = true;
+    missles.forEach((missle, i) => {
+      missle.move(1, 0);
+      missle.draw();
 
-      ENEMY_SPAWN_RATE -= 5;
+      let enemy = missle.collides(enemies);
+      if (enemy) {
+        enemy.killed = 1;
+        enemy.color = 'red';
+        enemy.shape = '*';
+        missle.dead = true;
 
-      score++;
-    }
+        ENEMY_SPAWN_RATE -= 5;
 
-    if (missle.dead) {
-      missles.splice(i, 1);
-    }
-  });
+        score++;
+      }
 
-  enemies.forEach((enemy, i) => {
-    // move with speed
-    enemy.move();
-    enemy.draw();
+      if (missle.dead) {
+        missles.splice(i, 1);
+      }
+    });
 
-    if (enemy.dead) {
-      enemies.splice(i, 1);
-    }
+    enemies.forEach((enemy, i) => {
+      // move with speed
+      enemy.move();
+      enemy.draw();
 
-    if (enemy.killed == 3) enemy.dead = true;
-    if (enemy.killed < 3) enemy.killed++;
-  })
+      if (enemy.dead) {
+        enemies.splice(i, 1);
+      }
 
-  ui.cursor.goto(0, 0).yellow().write(`Score: ${score}`);
-  ui.cursor.reset();
-}, FRAME);
+      if (enemy.killed === 3) enemy.dead = true;
+      if (enemy.killed < 3) enemy.killed++;
+    });
 
+    ui.cursor.goto(0, 0).yellow().write(`${i18n.t('spacecraft.score')}: ${score}`);
+    ui.cursor.reset();
+  }, FRAME, i18n);
+}
 
 ui.onKey('right', () => {
   player.move(1, 0);
@@ -103,7 +105,7 @@ ui.onKey('space', () => {
 
   enemy.speed = () => {
     return [Math.random() > 0.9 ? 0.4 : 0, 0.06];
-  }
+  };
 
   enemies.push(enemy);
 
@@ -111,6 +113,6 @@ ui.onKey('space', () => {
 }());
 
 process.on('exit', function() {
-  ui.cursor.horizontalAbsolute(0).eraseLine()
+  ui.cursor.horizontalAbsolute(0).eraseLine();
   ui.cursor.show();
 });
diff --git a/src/tanks.js b/src/tanks.js
index bb9c693..73089be 100644
--- a/src/tanks.js
+++ b/src/tanks.js
@@ -1,4 +1,3 @@
-import Unit from './classes/unit';
 import Tank from './classes/tank';
 import Interface from './classes/interface';
 
@@ -14,14 +13,14 @@ two.go(ui.columns - 10, ui.rows);
 
 let stop = false;
 
-function loop() {
+function loop(i18n) {
   if (stop) return;
 
   ui.clear();
 
   if (one.dead || two.dead) {
     let num = one.dead ? '2' : '1';
-    const msg = `Player ${num} won!`;
+    const msg = i18n.t('tanks.playerWon', {num: num});
     ui.cursor.red();
     ui.cursor.bold();
 
@@ -50,12 +49,12 @@ function loop() {
 
   ui.cursor.goto(0, 1);
   if (turn() === one) ui.cursor.hex('#54ffff');
-  ui.write('Player 1');
+  ui.write(i18n.t('tanks.player', {number: "1"}));
   ui.cursor.reset();
   ui.cursor.goto(0, 2);
-  ui.write('Health: ' + one.health);
+  ui.write(i18n.t('tanks.health', {value: one.health}));
   ui.cursor.goto(0, 3);
-  ui.write('Angle: ' + parseInt(one.angle));
+  ui.write(i18n.t('tanks.angle', {value: parseInt(one.angle)}));
 
   two.draw();
   two.bullets.forEach((bullet, i) => {
@@ -75,29 +74,27 @@ function loop() {
 
   ui.cursor.goto(ui.output.columns - 10, 1);
   if (turn() === two) ui.cursor.hex('#54ffff');
-  ui.write('Player 2');
+  ui.write(i18n.t('tanks.player', {number: "2"}));
   ui.cursor.reset();
   ui.cursor.goto(ui.output.columns - 10, 2);
-  ui.write('Health: ' + two.health);
+  ui.write(i18n.t('tanks.health', {value: two.health}));
   ui.cursor.goto(ui.output.columns - 10, 3);
-  ui.write('Angle: ' + parseInt(two.angle));
+  ui.write(i18n.t('tanks.angle', {value: parseInt(two.angle)}));
 
-  setTimeout(loop, FRAME);
+  setTimeout(loop, FRAME, i18n);
 }
 
-loop();
-
 ui.onKey('down', () => {
   if (immoblize) return;
 
   turn().angle -= 1;
-})
+});
 
 ui.onKey('up', () => {
   if (immoblize) return;
 
   turn().angle += 1;
-})
+});
 
 ui.onKey('left', () => {
   if (immoblize) return;
@@ -135,10 +132,14 @@ ui.onKey(() => {
 
     loop();
   }
-})
+});
 
 let TURN = true;
 function turn() {
   if (TURN) return one;
   return two;
 }
+
+export default function(i18n) {
+  loop(i18n);
+}
diff --git a/tanks-es.gif b/tanks-es.gif
new file mode 100644
index 0000000..bfbfaaa
Binary files /dev/null and b/tanks-es.gif differ