Duality ZF is a space shmup coming soon to Xbox LIVE Community Games. The trailer is just above.

What really attracted me to this game is how polished it looks, plus some of those game modes... 4 player dual control? 8 ships blasting around the screen at the same time? Bullet Hell mode? Erm... gimme?

If this is your kind of thing, it'll cost 400 MS Points when it's released.