Play As Buzzsaw:
To play as the VCL champion beat the game in every game mode (Eliminator, Deathmatch, Endurance).
A "Chain" of Destruction:
When you are in VCL Coliseum, shoot out the rockets on the sides of the big T.V., in the middle. Once it falls, go to the spring board on the slanted side and bounce up to the top where a chain gun is.
In the aircraft carrier level, blow up all jets until there is a very large explosion. There should be a section of ship missing, go down into it and there will be a chain gun and a mini nuke. To get back out go through the blue portal.
Thanks to Revolution readers Tommy, Drew and Chromium!