To me the challenge was making a game whatsoever. I've never finished a game except for a couple small joke games (of the type that you make for your friends, and the games take 5 seconds to play). I had to learn how to use GameMaker during the jam, and I had to learn to write GML scripts in order to make the game I wanted. Even though my game ended up a fairly lame demo version, I'm very happy that I have anything at all, and I didn't give up! :-) I feel like I learned a lot about programming, and I will keep working to make a full version of my game.