The Timesplitters series has always been known for its campy humor and exciting, if cartoony, first person shooting. The second game in the series is a vast improvement over the first, although the lack of online play does hurt it a bit. Nevertheless, it is a fun romp with a vast array of goofy looking characters to choose from. Seriously, the characters are the best part (blasting monkeys while playing as a duck with a hat is quite enjoyable).
The game moves along smoothly although it doesn't really have a coherent storyline. You'll often find yourself confused by the big time jumping "plot". It doesn't make much sense to tell the truth but it doesn't really matter. It's just exciting fun most of the way through. The game bogs down a bit in a few levels in my opinion. A few of them feel more like work than play. Even so, most of the game is good cartoony violence and it has nearly endless replayability. The custom battles you can design can vary quite a bit and are very fun.
I would recommend the game very highly although the third game in the series, Timesplitters 3, is already out and quite affordable as well. Still, it's a good time and a worthy addition to any game library.