I like the "expanding your dungeon" concept a lot, it's quite fun, and I think have lots of potential. But I can imagine that people can easily cheese the system. The gameplay is decently smooth and fun, and I think this could work quite well as a full release with more content and balancing. A boss battle would be nice :)
Other things I like:
- Weapon to choose from
- Rooms are not just reskins but have their unique quirk
- Cosy music
- Cute artstyle
Suggestions:
- More variations on rooms and weapons, but I guess for a jam and prototype this is already good
- Using icons for the information instead of text? Would make the game feel more polished
Anyway, the game is super well done and polished, and I think you all did a very good job making the game! Well done!