Hooray! We can both draw and move the snake! Of course, having our users
idea, so we're going to have CHUNK execute the move and draw commands for us.
To get this function running we'll use our CHUNK game engine to CALL the executeNTimesPerSecond function. It does exactly that, to do this executeNTimesPerSecond takes in two arguments. The first arugement advances the game, and the second tells it how many times to move per-second.
Bam! Now the snake moves down until it runs off the game screen.
Because functions are just another kind of value (like numbers, arrays, objects, strings,
etc.) we can pass them as arguments to other functions.