I've just finished version 1.0 of my Enemy Spawn Hell shooter game, Aster. I call it an enemy spawn hell game because enemies are always spawning around the level and you have to try not to get killed. So, it's like bullet hell, but with enemies.
Anyway, I do have ideas for extending the game somewhat, but I'm pretty happy with it as-is and want to get started working on my February 1GAM a month entry, so I'll re-visit this in the near future. If you guys have any suggestions please don't hesitate to let me know on this thread.
The game can be found on the Scirra Arcade at http://www.scirra.com/arcade/shooter/3085/aster (sorry, still can't post links yet )