My bad, 7D roguelike, or making a rogue-like game in 7 days. Still too sleep deprived after two weeks of dance classes + parties and coming back to work. Three coffees a day are the bare minimum.

The Ludum Dare 48 hour game making competitions are also pretty fun. A relatively low barrier to entry, a set theme, and a large community.

They probably won't help with sleep much, though. ;-)