Почему змейка не работает?

var canvas = document.getElementById('canvas'); 
var ctx = canvas.getContext('2d'); 
 
var width = canvas.width; 
var height = canvas.height; 
 
var blockSize = 10; 
var widthInBlock = width / blockSize; 
var heightInBLock = height / blockSize; 
 
var score = 0; 
 
var drawBorder = function() { 
  ctx.fillStyle = 'Gray'; 
  ctx.fillRect(0, 0, width, blockSize); 
  ctx.fillRect(0, height - blockSize, width, blockSize); 
  ctx.fillRect(0, 0, blockSize, height); 
  ctx.fillRect(width - blockSize, 0, blockSize, height); 
} 
 
var drawScore = function() { 
  ctx.font = '20px Courier'; 
  ctx.fillStyle = 'Black'; 
  ctx.textAlign = 'left'; 
  ctx.textBaseline = 'top'; 
  ctx.fillText('Score: ' + score, blockSize, blockSize) 
} 
 
var gameOver = function() { 
  clearInterval(intervalId); 
  ctx.font = '60px Courier'; 
  ctx.fillStyle = 'Black'; 
  ctx.textAlign = 'center'; 
  ctx.textBaseline = 'middle'; 
  ctx.fillText('Game Over', width / 2, height / 2); 
} 
 
var circle = function(x, y, radius, fillCircle) { 
  ctx.beginPath(); 
  ctx.arc(x, y, radius, 0, Math.PI * 2, false); 
  if (fillCircle) { 
    ctx.fill(); 
  } else { 
    ctx.stroke(); 
  } 
} 
 
var Block = function(col, row) { 
  this.col = col; 
  this.col = row; 
} 
 
Block.prototype.drawSquare = function(color) { 
  var x = this.col * blockSize; 
  var y = this.row * blockSize; 
  ctx.fillStyle = color; 
  ctx.fillRect(x, y, blockSize, blockSize); 
} 
 
Block.prototype.drawCircle = function(color) { 
  var centerX = this.col * blockSize + blockSize / 2; 
  var centerY = this.row * blockSize + blockSize / 2; 
  ctx.fillStyle = color; 
  circle(centerX, centerY, blockSize / 2, true); 
} 
 
Block.prototype.equal = function(otherBlock) { 
  return this.col === otherBlock.col && this.row === otherBlock.row; 
} 
 
var Snake = function() { 
  this.segments = [ 
    new Block(7, 5), 
    new Block(6, 5), 
    new Block(5, 5) 
  ] 
 
  this.direction = 'right'; 
  this.nextDirection = 'right'; 
} 
 
Snake.prototype.draw = function() { 
  for (var i = 0; i < this.segments.length; i++) { 
    this.segments[i].drawSquare('Blue'); 
  } 
} 
 
Snake.prototype.move = function() { 
  var head = this.segments[0]; 
  var newHead; 
  this.direction = this.nextDirection; 
 
  if (this.direction === 'right') { 
    newHead = new Block(head.col + 1, head.row); 
  } else if (this.direction === 'down') { 
    newHead = new Block(head.col, head.row + 1); 
  } else if (this.direction === 'left') { 
    newHead = new Block(head.col - 1, head.row); 
  } else if (this.direction === 'up') { 
    newHead = new Block(head.col, head.row - 1); 
  } 
  if (this.checkCollision(newHead)) { 
    gameOver(); 
    return; 
  } 
 
  this.segments.unshift(newHead); 
 
  if (newHead.equal(apple.position)) { 
    score++; 
    apple.move(); 
  } else { 
    this.segments.pop(); 
  } 
} 
 
Snake.prototype.checkCollision = function(head) { 
  var leftCollision = (head.col === 0); 
  var topCollision = (head.row === 0); 
  var rightCollision = (head.col === widthInBlock); 
  var bottomCollision = (head.row === heightInBLock); 
 
  var wallCollision = leftCollision || topCollision || rightCollision || bottomCollision; 
 
  var selfCollision = false; 
 
  for (var i = 0; i < this.segments.length; i++) { 
    if (head.equal(this.segments[i])) { 
      selfCollision = true 
    } 
  } 
 
  return wallCollision || selfCollision; 
} 
 
Snake.prototype.setDirection = function(newDirection) { 
  if (this.direction === 'up' && newDirection === 'down') { 
    return; 
  } else if (this.direction === 'rigth' && newDirection === 'left') { 
    return 
  } else if (this.direction === 'down' && newDirection === 'up') { 
    return; 
  } else if (this.direction === 'left' && newDirection === 'right') { 
    return; 
  } 
 
  this.nextDirection = newDirection; 
} 
 
var Apple = function() { 
  this.position = new Block(10, 10); 
} 
 
Apple.prototype.draw = function() { 
  this.position.drawCircle('LimeGreen'); 
} 
 
Apple.prototype.move = function() { 
  var randomCol = Math.floor(Math.random() * (widthInBlock - 2)) + 1; 
  var randomRow = Math.floor(Math.random() * (heightInBLock - 2)) + 1; 
  this.position = new Block(randomCol, randomRow); 
} 
 
var snake = new Snake(); 
var apple = new Apple(); 
 
var intervalId = setInterval(function() { 
  ctx.clearRect(0, 0, width, height); 
  drawScore(); 
  snake.move(); 
  snake.draw(); 
  apple.draw(); 
  drawBorder(); 
}, 100); 
 
var directions = { 
  37: 'left', 
  38: 'up', 
  39: 'right', 
  40: 'down' 
} 
 
$('body').keydown(function(event) { 
  var newDirection = directions[event.keyCode]; 
  if (newDirection !== undefined) { 
    snake.setDirection(newDirection); 
  } 
})

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script> 
<canvas id="canvas" width="400" height="400"></canvas>