Geometry Wars: Retro Evolved (Xbox 360)
Geometry Wars proves that true 2D gameplay can have a home on a next-gen machine, even if it is only as a downloadable title. It may play very similarly to Asteroids or any other shooter of its ilk, but there's no denying its main pull is its spectacular next-gen visuals. Watching the wireframe grid get swept out of shape by powered-up weapons is a sight to behold - and when you start shooting the orbs of light and cascading sparks around a hi-def screen, you'll be as awed as a four-year-old on bonfire night.
The game uses old-school vector graphics which are the bones of 3D, but the core gameplay uses only 360 degree rotation through the 2D playing arena, so it's technically a 2D game. You're never seeing the action from behind your craft, which is a good thing as an unrestricted field of vision is essential in the packed environment. Not only is 2D a gameplay feature, but a necessity here.
Maybe the gameplay is too narrow to be afforded a full-price release. It does what it does and that's all. But as Xbox Live's premiere title, Geometry Wars proves that games don't have to be 3D to be impressive - and fun.