My biggest gripe would be the lack of a player health indicator. I also feel like making it so that your bullets don't go through the slot machines would both up the difficulty a bit, and make them act as expected (and make the AI harder to cheese)
Also, I'd recommend setting camera boundaries on the edge of the map so the player can't see the empty space outside of the floor texture. I'd also recommend making the respawn cost all your current money, I stopped caring about dying after a certain point.
Plus a small UI thing that would add a LOT of juice is indicators/sfx every time you spend money on something. Whether it be gambling or respawning, there should be an indication that I'm spending money on it!
But overall you have a good foundation and a fun loop!