I agree with some of the other comments. I felt that there was something interesting and worth exploring, and loved how the level and character changed color as I entered a new area.
But, the controls and character movement eventually caused me to stop playing. I too experienced falling through floors, and strange jittery movement. It was hard to jump onto platforms, as the player would suddenly move erratically and cause me to jump past them.
I think if you figure out the player controls and fix the physics issues there is something really unique here!