I love the concept, reminds me of an old flash game with a similar one. I also really like the joke in the title screen where there's two sets of buttons for the hero and the guy you're actually playing as, but it might get super confusing. The art is also fantastic, and I love the fast-paced rock-paper-scissors gameplay.
The problem is the game kind of gets stale after a while. My high score was 466.8 distance, but it got fairly boring at half that. I know you say in-game that there'll be more monsters, but I'd also really suggest having a larger weapon selection, too, like around 5-7. That'd make each monster more of a puzzle. If you do go for that, introduce the weapons in slowly, to make sure the player won't get too confused!
I'd also recommend making the health potions a little stronger.
Aside from that, the game was still pretty good, definitely needs to be expanded on in the future!