This game is beautiful. Awesome graphics I am a HUGE fan of 2D art and I loved the art of your game, congratulations for your project.
Gameplay: Awesome idea of jumping in the walls, making players avoid spikes and not making the respawn too slow, this really makes the differnce
Art: 10/10 I loved it, fantastic.
Sound effects: I would say it is ok, nothing to bad, steps were a bit louder than i expected and the music its not bad but it doesnt make you want to listen nonstop.
Overall great job for a starter this looks AMAZING, congratulations, now it will only get easier from here!