I love difficult platformers but I'm not a big fan of these games that make you play a level multiple times to learn where the traps are so it wasn't for me. That said, I beat every single level except 6 which after a lot of tries I could not figure out how to get past the final spike, on the hander hand I beat level 7 on my second try.
I like the simple art and the audio served it's purpose. I haven't played many games yet but this is the first one where the audio felt deliberate and the music didn't just annoy me. Initially I did not like the player movement or how floaty the jumping was but I quickly realized that it was necessary which in turn ended up making me appreciate the floaty jumps.
I know there is a market for these kinds of games so I'm not going to let my taste yuk that but I will say that the collisions on the spikes need to be perfect. I died a couple of times because the collisions were off and it was very obvious that there was still space between my character and the spike.