[reuben_tate]

Originally Posted by Kekeb

Be careful about extending beyond the bounds of your arrays.

This is the first thing I noticed myself. One possible easy fix if you don't want to deal with having a lot of "if" constructs to check if you're within your boundaries, is to implement circular boundary conditions and do your operations in mod n (i.e. having "whatever % n" in your code) where n*n is your grid size. In this way, the game will play as if it's a pacman universe (or you can imagine folding up your grid into a torus if you can visualize that :P).