It's really fun and it gets hard at times. Reviewers say it sucks but if your into this type of game then it's awesome.
The adventure mode is awesome. You go through around 20 levels throughout 5 differant environments. You can upgrade weapons and occaisonally transform into a monster. It gets really hard and there is a lot to do. The multiplayer is great too. The game modes are deathmatch, team deathmatch, capture the flag (2 flags, teams), capture the flag (1 flag, ffa), monster hunter, monster dojo, king of the hill (teams), and king of the hill (ffa). You probably know most of those except monster hunter and monster dojo. Monster hunter is a game type where everyone starts as humans to do free for all (ffa), but the first person to die is a monster. They have to kill the humans. If a human is killed, they become a monster and help kill humans. In monster dojo, the players try to survive endless waves of monsters. The game is really good. It's a but if you're into those games, if not a rent.