Game is alright, I like how the characters cycle while playing the song which is a nice touch and the game looks great!
Some feedback I would give is making the fake notes more obvious to the player that they can’t be played. Since they have the same shape as regular notes, but without color, players can mistaken that note for an actual note which could be confusing to players just starting the game. Also, I would love more game mechanics other than the fake note because the game at the core is the same as a 3-key VSRG with mines, so maybe something that has to do with the characters switching could be a game mechanic (Of course, time is a factor during the jam)!
Additionally, when the second song came up, the charting/mapping of it felt wrong as the first one was better (Maybe this is a browser issue when I played on web?).
In any case, I think it has potential because it is pretty beginner friendly with 3 keys, and maybe you could even expand it to 4 keys or more later for songs that are more challenging for players!