I've been looking forward to this for a good while, glad to finally get to play it.

Getting some '90s shareware/freeware vibes here, both visually and gameplay-wise. Although the core gameplay is simple, it's cool how you manage to introduce new mechanics in the levels themselves, rather than by giving the player new abilities. Visual clarity is mostly good, though I'm not sure if I like the bush enemies, sometimes I didn't notice them even though there isn't really much background decoration to mix them up with.

I'd like it if there was at least some horizontal slowdown in the air when you let go of the keys. Especially in places where you have other stuff to worry about, like fighting the wizard that shoots homing projectiles and you have to use the rising platforms to shoot him, it made the fight quite a bit harder, especially since your character also turns around when you try to correct your momentum.

The autoscroller part in the far left area of the waterfall level could use some tweaking. Since the camera doesn't follow you vertically, it's easy to accidentally advance too fast and then get hit by a bee or something while your character is out of view, and it basically feels like the game is punishing you for doing too well. Especially with the springs you could get way too high up, and then have to wait for the screen to catch up.

Anyway, great job overall. Gameplay is really smooth and I like the kind of creepy cute atmosphere you have here. I think I got all of the crystals, though I never found an area that looks like that last screenshot, is it even in the demo? I even tried messing with the start coordinates in the savefile to reach some normally unreachable teleporters in the hub, but they just crash the game.