This has a good mechanics. It feels like this is supposed to a rhythm game like dance dance revolution. The art style for this game is also great and I love it. The music is also great; it's cinematic. I think this game is yet to be completed so here's some of my comments.
It would be better if there's like an clear indicator like a line in piano tiles to show when should i hit the arrow keys. I think id this problem is solved, the game would be much better and much more enjoyable.
Overall, it's a nice game for this game jam. Good job and congratulations!