I found this to be frustrating but not necessarily fair, between the already noted background issues and hitbox feeling a little too big. Design wise the opening where you fall onto the semi-spiked platforms I think actually teaches the player that spikes are very dangerous, when I think you want them to first learn that they can walk through them? Made getting to the part right after feel like some joke. Of course I read that I could walk through the spikes and then it made sense. As chill as the music was I don’t currently have the patience for this primarily because with my keyboard setup the controls aren’t super comfortable for me, I made it up to the final staircase I think for the record.
Nothing wrong with making a hard game during a jam, but you’re far more likely to have people complaining something is too hard than too easy. I don’t think this is too bad difficulty wise personally, but it is very tight and requires a level of precision most people just don’t have with platformers. It is a solid game though, good work! :)