Hey, for your first game and first jam, this is great! I really like the overall theme of the game, right up my alley for what I like to see in a Magical Girl story. The distorted black and white graphics work pretty well and have a good unsettling feeling to them. The frantic piano music also fits surprisingly well.
My biggest critique would be in the gameplay. I kind of wish that the character auto-ran, so that I'd only need to worry about jumping and attacking. That or make it so the player doesn't fall off the screen on the left. That would certainly make the game easier, but increasing the enemy aggression could fix that. I made it to the enemies that fall from above, but not much further.
Nice work! Keep making games and jamming. :)