Many (many!) moons ago I was inspired by this ai-junkie project to build my own version. The project uses a genetic algorithm to train the neural nets driving the agents which need to collect the 'food'.
I took it a little further than they did, I had 'poison' to avoid and I toyed with different fitness functions and (what we would today call) 'deep' neural nets. All in all it's fun to see the different behaviours and strategies for collecting 'food' and avoiding 'poison' play out.