Very nice game!
Surprisingly deep, too.
Initially, I thought it was far too hard, but then I realized that you can walk into a wall to skip your turn (maybe you should add a key for that?) - that was revelation #1.
After that, hunger became the only real danger, as healing items are plentiful and the majority of enemies are harmless. Now I'd get to around floor 20, die of starvation, and then a ghoul, giant skeleton or ghost would finish me off. At this point, I was thinking the whole skeleton-vs-living mechanic was a bit pointless, as once you got far enough to start encountering ghouls and giant skeletons, it became impossible to survive long in the skeleton form. I was ready to suggest you get rid of the health system - maybe have 2HP is alive, 1HP is skeleton, 0HP is ghost, and each form has special abilities and vulnerabilities, and there are more opportunities to swap between them so there's a puzzle element to it, or something like that...
And then I played again, but thought I'd try "cheating" a bit. Instead of drinking the purple potion right away, I went as far as I safely could with the skeleton (5 or 6 floors, until ghouls started showing up), taking advantage of the fact that it doesn't need food, and completely clearing out the levels of all enemies and gold. Then I went back to the starting screen, drank the potion, and started over but with a few thousand gold in the bank to spend on food. This time, I got to floor 43 before starving to death, and again being finished off by a ghoul.
And then I suddenly realized how I was *supposed* to be playing the game. I'd always figured that once you're reduced to skeleton form, it's basically game over, since you won't be able to advance much further before a ghoul or giant skeleton finishes you off. However, I'd completely missed the fact that you can go back to previously visited floors, thoroughly clear them out, picking up all the gold which you skipped on the first run through in order to save food (which is no longer an issue in skeleton form), and then go back to one of the shops and use your new found riches to buy a purple potion.
Of course, if you die again, you'll have to go further back to get another purple potion, and it will use more food to get back to where you were, so it could easily spiral - but as long as you keep making enough progress between deaths, it should be a viable strategy.