I didn't much enjoy the campaign play for this game; however, the multiplayer pretty much makes up for it.
For being a PS2 game, the graphics were pretty decent - especially the realistic blood splatters after being shot or killed.
The levels were alright, but could have been better. A lot of them were pretty boring, with no real places to hide and such, but the few levels that I unlocked and played on frequently were well worth my time.
I definitely loved the weaponry. My personal favorite gun was, obviously, the W.A.S.P., however nearly all of the guns were powerfully effective and easy to maneuver.
Overall, I believe that Red Faction II is worth the money (definitely), and you seriously need to check out the multiplayer section ;). It's definitely a game you'll regret missing out on.