🚀 go-pugleaf

On the prison level, in the area with the black tower and the turret
guns (outside of the cell block), try this:

Go to god mode and (after blasting the baddies) use the jetpack to fly
up to one of the turret guns.  If you get level with it, you can push
it around like a hockey puck!  It will just hang in midair..complete
with shadow..and keep firing away all the time.

In duke match you can play hockey with it...sort of.

You  can also push it into the secret area in the black tower.  It
will keep firing at you from inside the tower!

Gawd!  What a stupid Duke trick!