app.js

// Check Collision
var checkCollision = function(anEnemy) {
  // check for collision between enemy and player
  if (
    player.y + 131 >= anEnemy.y + 90 &&
    player.x + 25 <= anEnemy.x + 88 &&
    player.y + 73 <= anEnemy.y + 135 &&
    player.x + 76 >= anEnemy.x + 11) {
    console.log('collided');
    // Position player after Collision
    player.x = 202.5;
    player.y = 383;
  }

  // check for player reaching top of canvas and winning the game
  if (player.y + 63 <= 0) {
    // if player wins, add 1 to the score and level
    player.x = 202.5;
    player.y = 383;
    console.log('you made it!');

    ctx.fillStyle = 'white';
    ctx.fillRect(0, 0, 505, 350);
    // pass score as an argument to the increaseDifficulty function
    score += 1;
    gameLevel += 1;
    console.log('current score: ' + score + ', current level: ' + gameLevel);
    increaseDifficulty(score);
  }

  // check if player runs into left, bottom, or right canvas walls
  // prevent player from moving beyond canvas wall boundaries
  if (player.y > 383) {
    player.y = 383;
  }
  if (player.x > 402.5) {
    player.x = 402.5;
  }
  if (player.x < 2.5) {
    player.x = 2.5;
  }
};

// Increase number of enemies on screen based on player's score
var increaseDifficulty = function(numEnemies) {
  // remove all previous enemies on canvas
  allEnemies.length = 0;

  // load new set of enemies
  for (var i = 0; i <= numEnemies; i++) {
    var enemy = new Enemy(0, Math.random() * 260 + 50, Math.random() * 256);
    var enemy_rock = new Enemy_Rock(0, Math.random() * 260 + 50, Math.random() * 256);

    allEnemies.push(enemy, enemy_rock);
  }
};