I really love the look of this. It's cool how dynamic it feels, thanks in large part to the moving camera. Though while visually cool, that same movement did sometimes make it difficult for me to be able to parse which side a bullet was heading towards. Particularly Sakuya's first phase gave me trouble for this reason. Don't know if this is intentionally part of the challenge or not (that is, being able to parse where the bullet is coming from), but I think some sort of additional visual could've been helpful. Color coding the bullets to each direction is the first thing that comes to mind, but I'm sure there's other ways.
To jump off another comment, it feels a lot like a rhythm game. Because it is basically DDR but without music and obviously contextualized very differently. An in-rhythm soundtrack would've added a lot, even perhaps just some percussion, but I understand if that wasn't in the cards. Proper rhythm games are a lot of work, not even including actually making the music itself.
While there was no music, there were at least some good sounds. It particularly made punching feel very satisfying lol
Good work overall