I like the idea, and the audio and visual parts are cool and engaging, but the gameplay itself felt like being trained to press a spacebar constantly and that was about it, sadly.
Maybe using WASD (with W representing beats on the top, A the beats on the left, etc) would make it feel more like a game. Edit: although I see it was inspired by a one-button game, so maybe instead my suggestion would be for adding a way to discourage just mashing spacebar even when there's no note to hit
It would be great to see this developed into something more fun to play as well as having good music and visuals. (I like hypnosis and rhythm games, so a combination is a cool idea.) Regardless, thanks for sharing.