It's not the best map for teamplay, as it's of a simply huge size. Players of both teams spread across almost all the level, and this makes good teamplay difficult. The main weapon is BFG10K. You must control it every second, as it allows you to control the quad more easily - the quad helps you to clean up the most part of the level. How to do it: you take BFG10K, go to the red armor or the Megahealth (they spawn at the same place), take one of them, let a teammate (better one with the Rocket) know about it, go tot take the quad, while the partner is waiting for another red armor (Megahealth). Then he takes next BFG10K and Rocket.
Two other players must conrtrol the Railgun, Hyperblaster and yellow armor. From the window in the room with the Railgun you can help a teammate control the Rocket. Forth player can help in the meanwhile to take the quad, swimming from the water with the Chaingun.
It's usually difficult to organize total control on this map, so the quad plays the key role - don't forget to take it. Also be careful firing with BFG10K, as the level isn't quite open, and you can hurt yourself either occasionally kill a teammate. And don't forget that there's a lot of lava around - watch your step and don't fall into it.
