The controls feel excellent, and the main character is really funny! I did have a great time playing it, the level design was good. I liked the fact that you get rewarded for fighting enemies, and it does not feel like farming at all. Overall, it is really well put together.
Maybe, to add some criticism, the background feels a bit too dead for my taste. Given the feel of the game, some simple background or, if you did not want any because of the classic theme, a more lively color would be appreciated (not in the cave, the cave is just fine).