This concept has a lot of potential! I didn't realize I was in the tutorial at first and thought the game wasn't working, so it might help to have an intro screen with the instructions and then drop you into the game. It's easy enough to figure out without a complex tutorial. Good sounds and music too. I could see this being really fun, especially if you had some kind of system where you have to figure out which weapons are the most effective for which monster. (For example: instead of killing them in one hit, they do X or Y damage.)