Well I have a few more ideas, but it's taken me months to get the game to where it was when I uploaded it, and I'm not sure how much further my python knowledge can take it.

I'll do what I can though

New ideas:

Multiple monster types per level
Some monster types split in 2 when attacked
Items to temporarily slow monsters
Introduce AI pathing to actively chase player
Custom key bindings
Multiple block types per level
Scrolling levels, so levels can be much bigger

Just the ones I can remember at the moment