Playing with lifts
If you jump off a lift before it's too high, you can land without damage and it'll start to come back down again. If you then run underneath, it seems to stop and go back up to avoid squashing you. I mention all this because the underside of a lift is actually worth seeing. It spins quite fast as the lift rises. Also, if you've got an overshield (there was one on the first floor) you can survive the fall down into the brightly lit area below. With the second and third lifts, you'll actually find the Monitor down there and can have a close look at him.
Something else to do is to jump off a lift into an outlet, part way up.
You may also be able to work a bit of Flood fighting into all this lift play, if you've got a bunch chasing you. You can get them onto the lift. I also notice that when spores get onto the lift, their motion can get rather glitchy. They sometimes look as though they're swimming partly below the surface, and they sometimes appear to be on their sides.