The classic 1-bit look of the enemies and UI works very nicely, but I feel it's a bit incongruous with the much-more-detailed environment textures? Since there's so much more going on in them I feel like they draw attention away from the parts of the game that matter mechanically. This might be one of those strange cases where the game might have benefitted from something a bit close to a wireframe dungeon?
Some of the enemies seemed pretty tanky; the first one I encountered took more than 20 attacks to kill, which is a lot when the attack animation takes five seconds!
Overall, though, the base idea seems fairly solid? With a bunch more equipment and options, and a more streamlined user experience, I think it could work.