I noticed on level 8 that i could get in the relic room by dashing (->+s), though this also triggered the plate that closed it. Then for some reason I decided to use the dolphin slash like move (/\+s) next to the wall on the left, glitched through, and fell out of the stage. This also worked on the right hand side, but that just glitched me out of the room. I could also replicate it very easily every time. It does not work on every wall, only some, I'm not sure what's causing the glitch. Also knocking the first enemy on level 8 upwards off the ladder would teleport him out of the map. Note also that fixing the first glitch would result in a softlock on triggering the second plate while dashing, as you would be trapped in the relic room.
Edit: Added screenshots: http://steamcommunity.com/profiles/7656 ... crollTop=0
(sorry, I don't know how to put images up here)