Awwe, so cute! And such a clever design. As tsuneko said, so many systems being interconnected through the "vitality" number is really interesting, and makes you consider things in weird and interesting ways. Wings sure can be worth the 10 steps it costs to get them. Is the map going to save you the 4(or 5?) missteps it costs to buy? Will the sword actually take out 10 damage on all the enemies you'll face? (and will the other enemies you could avoid drop enough vitality on death to be worth moving out of your way to fight them?)
Truly fascinating in its simplicity. Oh yeah and the art is fantastic too.