I think I installed the wrong one but I managed to clip OOB
Viewing post in Untitled 3D JRPG Prototype jam comments
Yes, you seem to have downloaded one of the previous demos. That's feedback too, I will make it clearer, maybe hide old demos.
Getting out of bounds is intentional for the prototype as long as you have clipped through the ceiling and not one of the walls. (I just thought it was funner to leave it in than having nothing to do, like an easter egg but since no one pointed it out before you might be the first to have found it) The actual game probably won't have jumping so this won't be a problem. If you clipped through a wall rather than the ceiling then it's in fact a bug.
Thanks for playing my game!