Alright, so I just went through the game, and I was very pleased with the aestetics of it, and how nice the platforming feels. I love it. I know this is just a demo, and this is something you'll probably cover, but skipping text once read would be nice. Same thing for boss fights intros. The levels are well designed, adn I never felt lost. I enjoyed every aspec tof it, and the sfx were pretty charming.
You're doing great so far. Keep it up!