Comments

Oh, and I just tried putting another button on the other side, by cloning the first, and of course that didn't work because I can't target two things with a trigger_changetarget.

Well, the button is a two-way one, meaning you can close it as well, and you can only really get trapped on the other side if you do a runner.

Helpful hint: Don't block all of the doors at once. You'll break it. The doors will eventually close, but you get the annoying stuck door sound.

The other entries to the compo (including mine) have some serious competition.