The game has a lot of ways it could improve, but in it's current state, it leaves a lot to be desired.
First things first, get rid of a certain annoying bug. Seemingly randomly, you will be teleported off-screen. This is annoying as all hell and I hope it gets fixed ASAP.
Second, try to find some people to work with. As of now, it looks like it was a bunch of assets thrown together into a game, with a mixture of clashing artstyles. These people could also give inside feedback for ideas as they come out and maybe give you their own ideas.
And this is something I'm not 100% sure on, but I think you could change the enemies and environment to be a bit more varied. Some platforms could be bigger while some could be smaller. Some enemies could move across platforms and some could be taller.
I may be a bit too harsh, considering how you stated this is for learning purposes, but this is how I feel towards the game. I hope you can take this into account for either updating this game or working on new projects.