Wow, thanks for the extensive review. The arrows and final boss I was aware of, but I'll have to look into the colosseum issue.
If you're curious, I spawn the arrows outside the skeleton's hit box, so if they're up against a door the arrow will spawn on the other side. I meant to fix this by having the skeletons only enter their "attack" state when they have line of sight to the player but I ran out of time.
As to the boss... something is wrong with his state machine but I'm not quite sure what yet.
Thanks again! I really appreciate the feedback.