setFood()

Max,

i refactored this function and as per console.time() it is a lot faster.
The original version is executed in 0.300-500ms, this one in 0.010-0.020.
I found that interesting.

function setFood() {
var randomX= Math.round(Math.random() * (grid.width - 1)),
randomY= Math.round(Math.random() * (grid.height - 1));

  if(grid.get(randomX, randomY) === SNAKE) {
    setFood();
  } else {
    grid.set(FRUIT, randomX, randomY);
  }      

}

Thanks for the great tutorials.

[redxtreme]

I think the issue with this fix would be when the snake gets very large, it will take many cycles to eventually find an empty location. I haven't tested this, it just appears to be a flaw of this algorithm.