First off, art, effects, music, polish, is all AMAZING. Everything feels fluid, every sprite looks great, and all of them have some fantastic looking animation. Overall, a brilliant job on all of the assets and the polish!
Despite how amazing all of the art is, this game is seriously lacking in gameplay, which is ok to start out. The entire thing is quite literally just spamming z with very little adjustments to movement. Every enemy is a health sponge with the only obstacle being to slightly adjust your character's position and continue relentlessly spamming z (with the exception of the flying eye), and the final boss is a testament to that. No doubt it FEELS amazing to hit enemies and make them die, but there really is no diversity in the types of enemies and how to defeat them. The flying eye is the only enemy who does really mix it up, but at the end of the day that enemy is just a faster version of the other enemies with less health, and are dealt with the same way, moving back a bit and spamming z, just with a little bit more speed this time.
The abilities were something to change it up I suppose, which again, all of the abilities feel and look amazing to execute, but really they're also quite simple and only do a little bit to mix up the game.
There really is limitless places for improvement here, maybe you could have added platforms to jump around on, or an enemy that shoots projectiles that make the player dodge and need to out maneuver all of the outcoming bullets. Maybe you could dash in different directions, and also make the enemies less abundant in health, or maybe let the player choose a damage upgrade, that would feel like satisfying growth in a game that revolves around hitting.
My idea is that the art, animation, polish, music, and effect, all get 5 stars, but the gameplay gets two stars. As a tiny game project I think it's incredible, and there's definitely room for mighty growth, keep making great stuff like this!