Ah the art and designs are so freaking cool!! The last boss looks so epic B) The literal only art issue is with the floor being maybe too detailed? Id suggest trying to make the tiles larger so its a less complex thing that distracts from the characters :)
With the game play itself being so unique and full of potential I find it a bit lacking? Perhaps adding different bullet types or wall upgrades to make the game both more visualy and gameplay vise better! :D Tho there are some issues like the block meant to be dragged and launched in the tutorial not working and me not figuring out the heal item (maybe a mention of it in the tutorial?) Id also make the mana more noticable by adding something like an animation to it when its full? Cant really figure our how the player could keep an eye on both the bullets and the mana at the same time so hopefully you have better luck with that :D Last detail is maybe dont let the drag arrows grow to that size? o-o Its able to cover the entire screen haha! XD
Tho in conclusion I would say the game is freaking unique, amazing and full of potential! The animations are very well done, not too distracting but enough to add visual interest to the game! AH and the COLORS man! Really like those! :D Keep up the AMAZING work and hope to see more from you in the future!!! <3
(While some people say the game is too hard I really dont think so :0 I managed to beat it first try tho maybe do make a test boss with just a few bullets? :D so the player can get a hang of it uwu)