For me, this was the overall highlight of the Games for Blind Gamers 2 jam. I love music toys, and this is one of the best I've played. The audio design and visual design are each solid on their own, so the experience can be enjoyed by either blind or deaf players. And for players who are both sighted and hearing, the visuals enhance the experience of the audio without stealing attention. The mysteriousness of the controls encourages experimentation at first, and once you learn what each control does you can perform with more intentionality.
The only controls I don't love are the A/B/X/Y buttons. With all the other controls you can just jam with no worries, they might be somewhat random but everything will sound good no matter what. But A/B/X/Y are unpredictable and potentially discordant/jarring, and they have a huge impact on the sound so you will definitely notice. I didn't feel like I could be intentional with them, because I might get unlucky and play a "bad" note that changes the vibe in a way I didn't want. I ended up shying away from them, which is too bad because the visual effects they make are absolutely gorgeous.
The A/B/X/Y controls are primary/special, so whereas it's great that the other controls are always pleasant in any combination, I wouldn't suggest that for A/B/X/Y. I'd instead just make them more predictable, for example each button always has the same effect, or varies in a predictable way based on other controls being used. That would allow players to discover and repeat interesting combinations and progressions, without limiting them to just pleasant vibes.
Even with that one critique, this is a fantastic and very impressive creation, and I'm very much looking forward to seeing what comes next!