This was quite simple but I enjoyed it, the difficulty curve I think worked well. Found myself having to think a bit in the later levels and died a few times but nothing egregious.
Some of the collision is a bit iffy with the player still stuck to ledges even when visually standing completely off the block. But it wasn't a major issue for my playthrough. It actually kinda helped in a couple cases with long jumps. Speaking of the longer jumps I would probably make them a bit closer together because some of them it honestly felt like I was cheesing the players collision box.
As for positives, the art and sound effects were good, and the levels had a decent variety and good introduction of new mechanics.
Good work!