Really cool idea and level design, and the graphics are minimalistic yet great. Sounds great too.
Here are my suggestions:
1. Split the tutorial into chunks and put them inside very simple levels. I don't understand what the point of that block in the first level was and I was confused by it, partly because:
2. I really don't understand your keybindings. I kept trying to jump using w out of habit and having to jump to the void to restart the level, which by the way raises the question, why not put in a press [R] to restart? It takes seconds and makes the game feel much more polished, at least for me.
3. I think the arrows and the drawings you put on the level either confused me a bit since I had a solution in mind and trying to figure out what you meant was hard sometimes, or they immediately told me the solution. So, I think that the arrows mainly hurt the puzzles.
But I don't want to sound too negative, this is a really great game! These are just me nitpicking some stuff.