Thank you! This update was really necessary. I underestimated during the jam how important it would be to visually show buttons on/off position! Also really happy to see my music is enjoyable. I'm still a beginner in composing and using DAWs, so that's very encouraging!
As for traditional games mechanics, well, it's not really what I was looking for with this one. I really like in games the concept of just playing and enjoying music, without goals, challenge or score. In a way it's all about the appreciation of the moment. So even if recording it could be a great feature, it would go against the idea of "what only matters is now". My main inspiration is Panomarical, a game about just enjoying music and visuals. Now I won't venture here into the slippery field of what is or isn't a game, but you can think of it as a musical toy. :)
However, I do have some ideas to use that kind of mechanic into another type of game. Basically, instead of directly interacting on a UI with buttons, the player could explore a virtual space (2D or 3D, what fits the best) and find switches to make the background music change! That could be mixed with puzzles, or platforming, or even just exploration. Either way, I will certainly use what I've learned during this jam in other projects!
Thank you very much for the feedback!