Wow! The visuals look soo good. I also noticed the juicy effect (particle system) when we jump/land on platform. The controls are intuitive and the visuals is the key highlight of your game.
As for the fixes you need to make:
1. The game feels a little laggy. (Which you explained is caused by you forgetting to stop something at the start)
2. The level is too hard. For someone like me who has even completed games like celeste, I found your positioning of blocks to be a little less forgiving and due to which it was difficult to climb. I had to first read your comment about coyote time, but remember that not everyone will read it. So, the placement of blocks can be a bit better.
That's just the 2 things I found to be a little annoying, other than that the game is just amazing. The soundtrack, visuals and effects are all amazing.