Hey - this was super fun after the initial struggle kind of getting used to the control scheme - video games, am I right?
I agree with pretty much everything GJDZ said - most of which I was going to suggest myself. The Coyote Time thing especially - there was more than one time I was stuck about halfway through a level only to botch a jump because I was trying to be precise.
I think maybe putting a soft-save after some of the more complicated bits might be a nice "quality of life" feature, just because if a player has made it past a difficult bit only to eat it shortly thereafter can get frustrating. That being said...
I love the spear mechanic! The most fun I had was one of the times I had to start over and just burning through the first half of a level (as I had memorized it by that point) spearing enemies and then pulling it back, tossing it into a wall mid-jump, landing on it, and then hopping up and taking out another enemy. It felt, like... spear parkour?
Anyway, great work - I'd love to play (probably with a controller) a more polished version of this!