Ok, the idea is pretty cool and the multi layer parallax is absolutely awesome at the start, that your descending down a deep hole, but the execution is well, pretty horrible.
First of all, the worst thing about this game: THE CLOUD, I hate that thing so much, it's so glitchy, you don't even know how many times I died to that thing, because of it just not being where it's supposed to be, some times it's just blocking the path and I die, because im rushing to get back where I was, yes I know that when rushing it's easier to do in any game, but when you die because some dumb cloud was where it was not supposed to be, well that's very annoying. Also the cloud feels like a so lazy way to stop you from just jumping to the bottom, especially when it just teleports to where it needs to be.
Instead, to stop the player from just skipping sections, I would add fall damage, that's kinda hard to communicate, but maybe just make the screen tint more red faster your falling, so you know when your going to die and when not, of course you still don't really know will you die from a jump, but that's still better than dying to some random glitchy cloud.
Also there's way too little checkpoints, maybe it's just a skill issue, but it's kinda annoying to redo massive sections of the map to get back to where you just were. And I know how easy it's to make your game way too hard, because your so good at it, so it feels balanced, our game for example is way too hard, but still.
And then jumping from walls, it feels really glitchy, you should add coyote time, so even after falling from a wall, for a few frames, you can still jump, so it feels more fair, because right now, every time I try to jump from the wall, I just end up falling.
Also if you jump straight up from a wall, you can't jump again, if don't go away and back to the wall, and that's really annoying.
Also I don't really know can you do that in Godot, but post processing would look really good.
Also in the hole, the backgrounds parallax is cool, but you should add more layers to it like at the start, so maybe the background could have holes and there could be more background with different parallax amounts.
Also dying is really unsatisfying, you should add some camera shake and maybe some crazy death particles when you die. And then the camera should move to the start where a new player could be, now it just slowly moving to start looks really unsatisfying, and yeah.
Also you should add a jump sound effect.
And at start, it was really weird, because some walls you could climb some not, so you should have marked the walls that you can climb on.
Aand at the start, the pixel size for the font is bigger than the other pixels and that looks weird, so you should scale that down to be the same size.