Im quite pleasantly surprised. I've seen a lot worse first games on this site. Weight of the character is perfect and animations and ui are really nice but there are things that can be improved on.
-It annoyes me a bit that camera movement up and down is inverted and Im really not used to it. I would suggest to make it an option in the menu. Also camera sensitivity is way to big when playing with a mouse, It would be nice to be able to adjust it in options too.
-I would suggest to make it easier to hit enemies or at least make it more clear visualy how big your paunch hitbox is. Good trick is to make player attack hitboxes bigger and enemie attacks hitboxes smaller.
-Any platformer 3d or 2d needs coyote time. Aka make it that player can still jump like after 0.2 second of falling off the ledge.
(coyote time in celeste)
-I definitely suggest adding drop shadow to make landing on platforms easier.
-Add sound affects to any action that happens landing ,jumping collecting, even if something on the ui moves.
-In a lot of 3d platofrmers player is not actually in the center of the screen but more slightly lower, It makes player see more in front and less behind.
-I was unable to get the last crystal (the one with pushing off boxes) timing triple jump on that box that is slightly lower without any landing sound is a bit to hard.
Overall really good job for a first t