So I was doing some glitch hunting, and I managed to clip inside the first pillar by spamming crouch next to the trampoline thing. After exiting the building I was in some kind of floating state. I could move normally, but activating cristals was weird, and requires precise but unknown positioning. Same thing with the trampolines. It's as if everything was moved a couple meters.

I could easily enter buildings this way, and it seems like it's also possible to stand on top of white buildings. Apparently the buildings are empty inside, so it's not possible to climb them from inside unfortunately.

I'll look for other possible uses and other glitches.