The issue with this game primarily is lack of air control when jumping. I would get by with most of the other complaints but being a platformer and feeling like I cannot control my character seems like a huge no no unless you can convince me the player that there is good reason for it for the game to be fun. I did not see that here.
That being said if you turned this into a dive kick platformer all about moving around jumping and diving around that would be a blast of a game. My advice is to do just that.
Regarding the art its cool though being dedicated art team I was hoping to have enemy variants but in my playthrough only was able to kill my own sprites. Background art is job well done though both of these pieces together style wise do look different so I think inspo boards would have helped keep the two on the same page.
Overall the potential is there and with more time you could have made this into a fun arcading platforming one input fun!