Very interesting! I like the graphic style and gameplay.
Two thoughts on how you can make this game more accessible without significantly reducing the difficulty level:
1. In games where you get killed a lot (and here you get killed very often!), respawns should be super fast. Now it takes two mouse clicks. Maybe it's a detail, but in my opinion, if respawn required one click and not by mouse but by keyboard (preferably the space bar, which we use to jump anyway), I think the overall flow of the game would improve significantly.
2. Especially in the gamejam, when there are a lot of games to play, I think there should be a checkpoint after each level. I liked the game a lot, but level 3 beat me mainly because I had to start all over again with each death.
Still, very good job!