This is a fun game. The graphics are quite nice, too :)
I'm not sure about why is the character standing in an empty tile.
I think the core heart-shield-sword mechanic can be developed even more. Right now, all three objects are almost the same: they represent how many times can you crash against an enemy before dying. If you want, you can imagine that they are all hearts, and the game would work [almost] exactly the same. Spiders are an important difference here, as is capping each object at a maximum value, which requires the player to avoid picking items he already has maxed; however, I think that more differentiation may lead to more interesting decisions. For example, what if having a sword allowed you to hit stronger, so each hit with a sword equals to two (or 1.5) without one?