This is excellent! I'm not a huge platformer but I got so engrossed in this I completely forgot to come back to rate and comment, so obviously I had to play it all again then do it properly!
Echoing what everyone else mentioned, the control scheme is absolute bait with using spacebar for not jump, makes getting to grips with the mechanics so hard and still confuses even when you have been playing for a while. That and the overly sticky wall climbing are really the only things I struggled with.
Apart from that I think almost everything else worked great for me, the art style and sound design all fits together nicely, the gameplay is peak (frustrating at times but making you want to keep trying over and over). Absolutely has potential for post-jam work.