There's a very noticeable delay every time I try to dash that makes it impossible to attack some of the skulls without getting hit, in part because it seems to be bigger right as they're about to shoot. On top of that, if the character gets hit, right after I push the button, it seems to result in the same visual feedback as if I hadn't pressed the button at all. I also can't tell the difference between letting the character fall and pressing s.
At the start of the game, there seems to be text at the top, but gets cut off by the top of the game area. My resolution is 1366x768 in case it matters.
Despite the frantic gif you put for the cover art and overuse of particles each dash, the game feels slow. There's a lot of waiting for the skulls to not have shots blocking the way, especially the blue skulls. I played until I got to two blue skulls at once, and stopped because I was tired of waiting for a safe shot.
The tutorial calling itself "hand-holding" seems like it falls in the category of derisive naming that Extra Credits has discouraged in its videos. It also doesn't feel good to have the tutorial wait till after something bad happens to give instructions. I don't see any other listing of controls, either, so I'm not sure what alternative the game is expecting.
Lastly, your descriptions all mention kicking, but the character dashes.
