Man, this is a tricky one to review, I want to focus on gameplay so I'll get all the other things things first, visuals: really cool, love the background, the mouth expanding, the character, I love all the animations for the character, and the little dance they do when standing still, superb! Even the UI for collecting pentajumps and super speed looks nice, you really nailed the vibe! Music is great too, the upset stomach sounding music of world 1 is so cool and the more chilled out music for world 2 is nice as well!
But the gameplay, to start off I think the actual character movement aside from the gravity is very nice! It has a slight slipperiness but it feels very well tuned, reminding me a little of the Ori games. Jumping feels nice too, along with double and penta jumps. But oh boy the gravity... it just feels, off. The first super speed level really just confused me, every single attempt felt so different despite me doing similar things, I get that there is a slight momentum buildup and then jump at the right angle but man it just did not feel intuitive to me at all and nothing ever went how I expected it too, I feel as though you coded it perfectly but it's the sort of thing where you have to fake a lot behind the scenes to make things feel right to the player even if it isn't accurate (that could just be me though). And then one last thing is the gravity changing from planet to planet, now this is is done fine, this is much more of a me thing but it's really hard to wrap my head around which direction my left and right will go if I'm flipping onto the underside of a planet which wouldn't be too much of an issue if I wasn't also under the time pressure of the pentajump and then there's a little eye dude who want to ruin my day. I think a thin transparent ring around the planet that rotates clockwise constantly (you'd need a small part of the ring to be brighter than the rest) or something of the sort could help remind the player which direction to go.
So I think you nailed the genre of game you're making, I suppose it all comes down to me having a skill issue lol. I really hope this doesn't come off as mean or demoralizing cause you've 100% cooked here, these are just changes I'd want to enjoy the game more, really great work!