Quite a funny little game, seems to me like you nailed everything.
The different areas increase difficulty very well, the crisp controls compensate for the close combat that is always more risky, there is reward for exploration (so much that I had to go back to see what were in the rooms that I hadn't explored in my first playthrough), combat was well done, and a good dose of laughs at the end.
If I had one thing to say, but it is just me nitpicking, it would be good to have an indicator of health on the final boss just to know if you're halfway through the boss or almost finishing it. But that's just a detail and does not change my rating at all.
Congratulations!