OOB - In most corners you can get in or out of bounds by dashing into the wall at the right angle.

Level Skipping - By stepping off and back onto the staircase as the level transitions, you can trigger the end of that level again. This will cause the next level to be skipped. If you are fast enough, you can skip 2 levels. If anyone can get 3 skips that would be huge for any%, but I haven't been able to.

Warning: If you skip a boss level (With this exception of the final boss) the boss will still spawn in the middle of the next dungeon, and the stairs will not appear until you kill the boss. This might be faster to do, but if the middle of the room can be oob so I've been avoiding it.

Skipping the final boss level will send you straight to the credits.