I enjoyed playing it, but there are still somethings that can be improved.
I feel the player movement should be a little bit faster, or maybe you should add a "run" button. Also, it seems the player has a small acceleration instead of moving at top speed all the time, which is nice for making precise adjustments to his positioning, but I also died because of it, when trying to jump from the edge of a platform to another without enough momentum.
I can't control how high I can jump by releasing the spacebar key, but I think it's intentional, right? I can't say if this was a designe choice or not, but I liked having to commit to my jumps.