I couldn't break it much, but I noticed you could "downwarp" if you kept rubbing up against a corner on a ledge when there was ground below said corner
Video:
Also I'm too lazy to go back and record it but when I got the tree ending without getting the sacrifice thingy ending, going back into the second area after going back to the first area would show a blank end screen (i.e. just the "END" text with no subtext)