There are almost no words to explain how good this game is.
R&C: UYA is extremely addicting online and off. The gameplay is great and the choice of guns is wide. The "story" mode is pretty good and the sense of humor is aplenty! The wide variety of missions to accomplish make the game even better!
As for the multiplayer (online and off) is also very addicting. I really cannot describe why it is so dang fun! Maybe it is just shooting other people for no reason or maybe the feel of freedom walking around. Plus, the choice of first-person or third-person view is very convenient. Different skins gives us even more freedom!
The small Quark vid-comics add a break from the same shooting of baddies around the galaxy (even though shooting monsters never gets old)
Ever since R&C was released I have always had a feeling that it would remain for many years. And I think it will indeed. With the new Ratchet: Deadlocked coming up, R&C will have even more years to be a great.