Awesome visuals, beats Doom by a mile
The 4D rooms where someone can be in a room above you and shoot at you is really cool. The maps are so large and then room spinning makes it very hard to learn the map layout which is good.
Though this game is kind of like doom, it's way better. At least in this game you can see what your doing!
The only thing I have had problems with is the network connection. I continually get network error messages when trying to connect to a game. Sometimes the game is laggy, though that is sporadic. I have played some very smooth 8 player games.
Overall this is a very good game, I would definitely buy it again.