My personal favorite pasttime is called "Car Darts / LADA Roulette". Basically put a car on an elevated platform, place goredolls below and ahead of the platform (roughly where the car will land), and drive the car off the platform.
spawn a shadow mutant and make it big (not to big) and then make the big shadow mutant go in a big van and put the boss with the shadow mutant and then put a nuke next to the van and explode it with rocket launcher