Crazy idea
I was just looking at the Worms clone Hedgewars and noticed that it actually uses Free Pascal. It may be possible to hold an AI contest where we create bots for the game.
Some benefits:We don't need to create a game. It's already made for us and in good working state.
You'll be supporting an open-source game. If your AI is any good it may be inlcuded with the game.

There would be some drawbacks like it is only FPC and may be a tad to advanced for a first AI challenge. Furthermore it may be too easy to make the perfect shot for an AI. At least I've experinced that the already existing AI can make much better shots than I can. But as I wrote before, this was just a crazy idea ignited by the fact that I just discovered the game uses Pascal amongst other languages.