I need help with TNT: Evilution!!

In map 30,how do I get to the exit or kill what I am supposed to kill to finish the thing? I am in the room (I think it's the last room) where the icon of sin is flying around everywhere. Any help would be greatly appreciated.

Yeah i notcied that too...i can get to the Gatekeeper but i have no idea how to bring the damned pillar up...

you have to launch rockets into its brain while standing on the top step if i remember correctly