Not sure of the rip off part but when I saw the game play my first thought was of CupHead. Nothing wrong with that. I like the graphics. Wonder if it is just as hard to play?
Seems like the most signature things seeming that way are the jump animations (doing a constant tuck roll in the air) from the characters, and having them shoot projectiles from their fingertips.
I like the Cuphead animation approach enough that I’m willing to forgive it. Heck, if it was just advertised as “small studio makes low-budget Cuphead DLC” I enjoy Cuphead enough that it would still be interesting.