(v0.2) I've noticed graphical bugs in the combat sprites before getting the first gate key. Small at first, but more obvious as other sprites flashed in place of the rabbit's hurt sprites, then the rabbit's attack sprites.
As if the game is pulling sprite information from other area's of it's memory.
More minor issues would be some missing collision on some walls and props. An example would be a wall-blood stain in one of the first rooms.