Its just so friggin great.
Its got a ridiculous amount of content, every stage (dozens of them I tells ya) is swimming with depth and variety. Its induced the strongest case of "just-once-more-time-itis" that I've suffered since I lost my virginity. Yeah, its still Geometry Wars, but now its got really clever level design, loads of new enemies, good additions to the gameplay, and lots of great music. I just spent three hours in my shooter "Zone", it was gaming bliss I tells ya.
and on an unrelated note, Kane and Lynch is not bad. The multiplayer is pretty neat, and the shooting/team mechanics are well handled. Its a little bit rough around the edges though. You can feel safe about skipping it until its cheap or renting at your leisure.
Do have a good day all.