I like the concept of trying to limit the use of the red and blue blocks, but for most of the levels it seems like there's a set amount of presses you need anyway so it doesn't affect the gameplay, so some redesign in the levels to make this applicable would be an improvement in my opinion.
Also making the players movement speed faster can really help make them feel better, even if nothing else changes! some cyote time and jump buffer would have been great as well.