Thank you. 

Definitely agree on the walls and their triggers. I'll have to try a few things with them to see what looks and feels best.

As for the spiky walls, I'm assuming you mean the ones at the entrance to the rooms? I probably should've just made those a normal gate or door type graphic since they don't really do anything but show that it's blocked off.

Otto was intended to be unstoppable like in the original game, but for that to not feel unfair he would need some changes. I'm also thinking maybe it could some kind of difficulty setting, where on normal mode he could be stunned or something like that, and leave the unstoppable version for a harder difficulty.