I like how it looks. The other comments were saying that the controls feel bad. This is an issue and I will try to break down all the problems it has. But first I wanna say that I really enjoyed the abilities you unlock. They aren't your typical double jump, wall jump and dash and that's always nice.
I also really like graphics. They are simple yet charming.
The final boss was amazing. It took me a bit to understand how it works and I think sound effects would have gone a long way to make it easier to see how it works.
But now to the movement problems:
The jump lacks basic platforming features, like coyote time ( after you fall off a platform you should have a short amount of time to still be able to execute a jump ) and an input buffer ( pressing the jump button before touching the ground should still make you jump ).
The second issue is that the air mobility is just too much. It is very difficult to control where you are landing because of this . It is generally speaking better to have two different acceleration values. One for the ground and one for the air. But the game feels like it doesn't even use acceleration to begin with.
Another thing that would help with the speed issue would have been a variable jump height. An easy way to do this is by checking if the player is traveling upwards and if the jump key is released. If both are true just multiply your vertical speed by 0.25 or anything that feels good to you.
Another thing I noticed is that sometimes the jump input gets eaten. I have no idea why this is but I think it's worth looking into, to avoid this problem in future games.
For a first game this is fantastic. Keep it up.