I'm not thinking that the rendering is the main problem. While it probably is part of the reason the game is so slow, the game ran very fast before I started using tables to represent particles. I used to be using numbers. sand was 1 and wall was 2. I might have to go back to that system, but the if...

I'm making a falling sand like game. If you've never played one, you can play a good one here . The idea is that everything is made up of tiny particles. These particles react to each other in different ways depending on what elements they are. Right now, I have a very basic demo working very slowly...