Thanks for playing. I explained the combat on the game's page, since I ended up not having the time to make a proper tutorial. It's a bit unfortunate that the way itch.io is set up you can download the game without ever seeing it.
Actually I did see the game's page description and read the whole thing, maybe I didn't pay enough attention to the tutorial, I'm playing a lot of games in the jam and learning controls can be a struggle if it's not something typical.