New ideas (019 and beyond! Levelgen?)

I'll just start with some favorites from another game

Age of Empires II: The Age of Kings

•Death Match: Players start out with A TON of extra energy and health
•Regicide: If the King dies, the game is lost! (Basically Mothership)
•Wonder: Build the most expensive object in the entire game and hold it to score points

OK that's over with.
Virus: Cooties! Saw it on the list;p (Game Mode)
Martians: Invading UFO's are attacking everyone in sight! (Die and kill in one hit. Those little UFO's from asteroids, remember those? So fun)
Interceptor: Incoming missiles must be destroyed before they destroy your cores. (Missile Command style missiles, but guess who intercepts them._.)
http://my.ign.com/atari/missile-command