About the diagram, there's actually one in the pause menu (it only shows the spells you've discovered, but in the main menu everything is shown, I just didn't have time to point it out in a tutorial, unfortunately). But yeah, I'm definitely going to put a screenshot on the itch page, that's a great idea!
I hesitated to add a metronome because I felt like it sounded bad... haha but during playtests people asked for it to help players, so I'd need to find a sound that's not too intrusive for that.
But when you say you stuck to "fire and wind," that's actually my biggest problem right now, I'd like to find a way to "force" players to vary their spells so they play different sounds. I thought about enemies with resistances but I'm not a huge fan of the idea...
