Last weekend I participated in the Global Game Jam. In 48 hours, we made a game about a particle accelerator. With our game, The Small Bang Theory, we won the first prize of our location, and we have a chance of winning the national prize as well.
Due to a lack of artists, our team made a game which is all procedural. The graphics are procedural, and there are infinitely many levels. (Although you certainly deserve a honourable mention if you make it past level six …) The arcade-style game is available at the game jam site.