Cool game ! Love the art and the general vibe.
My only nitpicking would be with the controls (I played with a gamepad). I feel for a 2d retro game, being able to move with the d-pad would've felt more natural that the left stick (why not both ?) and shooting with B made it very hard to jump and then shoot since the jump is a hold, having the shoot on Y (left facing button) would've made it easier to jump and shoot with my thumb.