main.js

// Create our 'main' state that will contain the game
var mainState = {
  preload: function () {
    // This function will be executed at the beginning
    // That's where we load the images and sounds

    game.load.image('player', 'assets/player.png');
    game.load.image('wall', 'assets/wall.png');
    game.load.image('coin', 'assets/coin.png');
    game.load.image('enemy', 'assets/enemy.png');
  },

  create: function () {
    // This function is called after the preload function
    // Here we set up the game, display sprites, etc.

    // Set the background color to blue
    game.stage.backgroundColor = '#3598db';

    // Start the Arcade physics system (for movements and collisions)
    game.physics.startSystem(Phaser.Physics.ARCADE);

    // Add the physics engine to all game objects
    game.world.enableBody = true;

    // Variable to store the arrow key pressed
    this.cursor = game.input.keyboard.createCursorKeys();

    // Create the player in the middle of the game
    this.player = game.add.sprite(70, 100, 'player');

    // Add gravity to make it fall
    this.player.body.gravity.y = 600;

    // Create 3 groups that will contain our objects
    this.walls = game.add.group();
    this.coins = game.add.group();
    this.enemies = game.add.group();

    // Design the level. x = wall, o = coin, ! = lava.
    var level = [
      'xxxxxxxxxxxxxxxxxxxxxx',
      '!         !          x',
      '!                 o  x',
      '!         o          x',
      '!                    x',
      '!     o   !    x     x',
      'xxxxxxxxxxxxxxxx!!!!!x'
    ];

    // Create the level by going through the array
    for (var i = 0; i < level.length; i++) {
      for (var j = 0; j < level[i].length; j++) {

        // Create a wall and add it to the 'walls' group
        if (level[i][j] === 'x') {
          var wall = game.add.sprite(30 + 20 * j, 30 + 20 * i, 'wall');
          this.walls.add(wall);
          wall.body.immovable = true;
        }

        // Create a coin and add it to the 'coins' group
        else if (level[i][j] === 'o') {
          var coin = game.add.sprite(30 + 20 * j, 30 + 20 * i, 'coin');
          this.coins.add(coin);
        }

        // Create a enemy and add it to the 'enemies' group
        else if (level[i][j] === '!') {
          var enemy = game.add.sprite(30 + 20 * j, 30 + 20 * i, 'enemy');
          this.enemies.add(enemy);
        }
      }
    }
  },

  update: function () {
    // This function is called 60 times per second
    // It contains the game's logic

    // Make the player and the walls collide
    game.physics.arcade.collide(this.player, this.walls);

    // Call the 'takeCoin' function when the player takes a coin
    game.physics.arcade.overlap(this.player, this.coins, this.takeCoin, null, this);

    // Call the 'restart' function when the player touches the enemy
    game.physics.arcade.overlap(this.player, this.enemies, this.restart, null, this);

    // Move the player when an arrow key is pressed
    if (this.cursor.left.isDown) {
      this.player.body.velocity.x = -200;
    }
    else if (this.cursor.right.isDown) {
      this.player.body.velocity.x = 200;
    }
    else {
      this.player.body.velocity.x = 0;
    }

    // Make the player jump if he is touching the ground
    if (this.cursor.up.isDown && this.player.body.touching.down) {
      this.player.body.velocity.y = -250;
    }

  },

  // Function to kill a coin
  takeCoin: function (player, coin) {
    coin.kill();
  },

  // Function to restart the game
  restart: function () {
    game.state.start('main');
  }

};

// Initialize Phaser, and create a 500px by 200px game
var game = new Phaser.Game(500, 200);

// Add the 'mainState' and call it 'main'
game.state.add('main', mainState);

// Start the state to actually start the game
game.state.start('main');