By request, here is a demo, recorded on ACE difficulty, of level 6 from start to finish. It's pretty much a "walk-through," and I exploit nearly all of the available secrets and goodies.
There is one room I do not enter, however. Next to the recharge center, there is a room that contains a vulcan cannon and ammo. These powerups are pretty well guarded, appropriately enough by vulcan pigs. I feel that the bounty provided by this room is not worth the cost of obtaining it. Hence, I leave these goodies and the robots to be blown to bits by the self-destructing reactor.
Note: I have changed the name of this demo from L6Ace to L6WTAce to be more consistent with my other demos. The demo has not been re-recorded.