This game was clearly designed with the 64x64 resolution in mind, and it looks just like a lowrez-game ought to. Especially the player character. The movement and controls feel very good. Gamepad didn't work in browser, I had to download for it to work. (probably not your fault, but still a gripe)
I would have loved for there to be any sound at all, maybe something as simple as a bleep for when you attack and a bloop for when the monster attacks. I also didn't feel a strong sense of direction, since most rooms looked the same. I would suggest adding some markers or a minimap, so you don't get lost, especially in the beginning.