Great job on your first finished game!
I wonder if you even need to have levels with them individually, and with the diamonds? I feel like all of that was just building up to having red gates in the level and using q to switch, but I think you could've had those systems from the start and just built them up by level design.
I really liked having platforming challenges where I had to switch mid-air. It was fun and forced me to think about my jump before I committed. Would like to see further expansion on this by having some challenges where you have to pass through a red gate mid-jump and take advantage of that transformation.
But yeah, good job! I had fun with this.