first of all this is a really nice looking and feeling game, sounds somehow dont get annoying and graphics dont hurt to look at. but i did notice some big design faults that you might want to address, if you have problems with them i will also offer some solutions
Problem:
Lack of coyote time, in case you are unfamiliar with the concept coyote time is a small window of time after a player jumps off a platform where if they hit jump they will still jump even though they arent standing on any ground.
Solution:
Implement coyote time! its fairly easy to implement in most engines and makes the platforming of any game feel WAY better, humans are not computers so when we need to make a tight jump we will mostly hit a little late, this even exists in hardcore platformers.
Problem:
Re spawning, animation takes very long and it spawns you right at the beginning of the level, this becomes infuriating at even the second level and i was not able to get past that simply because of this, and alot of players will react in the same way
Solution:
Decrease respawn time possibly even to zero! and add checkpoints! its annoying to do some of the same challenges that you already beat over and over again just because you died to a different one further ahead, this is absolutely vital for difficult platformers but well used even in easy ones, it does not take away from the difficulty at all but VASTLY reduces the frustration since the player does not want to spend their time repeating old challenges and sitting watching their player die, they want to get back into the action and conquer new obstacles!
Problem:
The jump seems to activate when im holding down the jump button instead of just when i press it, this is not useful and becomes frustrating since often is the case i will make a hard jump but since im still holding down my character hops again and kills himself, because of human reaction time we probably arent going to let go in time for the second jump as the player lands not to register. this game seems to be very based around precision movement and something as reckless as that feels like using a shotgun to snipe
Solution:
Only check for if the player presses the button, after that first press another jump should not register until the player presses the button again. This way the player has fuller control of their own movements allowing for the precision platforming this game demands
Problem:
Unforgiving hitboxes. The hitboxes for the obstacles seem to be exact so if a player feels like they pulled off a narrow move they might just bump into it by a pixel and die, if its by a marigin that small the player will not feel like they deserves to die and get angrier.
Solution:
Smaller hitboxes! in your case maybe about 1 or 2 pixels, this can make all the difference. as if a player feels like they shouldnt have gotten hit but they just barely hit the obstacle, what they expect to happen will happen and they will make it, this will leave them happy. if they feel like they should have hit it and they dont, they will still be happy cause they will feel like they narrowly avoided it creating thrilling rewards!
Problem:
Lack of feedback. When i first died i did not even realized i was damaged until i could not move.
Solution:
Add more feel and feedback! blood, hurting sounds, character flashing or getting bounced, anything to convey that you just took damage or just died.
Overall it felt pretty nice and was really fun to play while i did, but these problems did get in the way of the experience and it hurts to imagine how much more you might have poured beyond where i got that I and many other players never got to experience because of those issues. Hopefully you continue developing this and release the full potential of this product! congrats on completing the jam and hope to see more from you soon!