Very nice entry!
Love the 1-BIT style with color accents! Music and sounds fit the game really well.
It's a feels a bit fast paced and "twitchy" at first, but that might just be that the camera follows the player 1-1, without any threshold, and that - to me - feels very jarring, especially with vertical movement.
The last boss could telegraph a bit more, since it feels like his attacks come out near instantaneously.
Other then those minor quirks, I did very much enjoy the game, and wrote this after my second playthrough!