Nice feeling 3D player controller. At first I thought the jumping was too floaty to be precise but the more I played it the more I realised it's actually quite well tuned for what the later levels demand of you.
It took me a moment to work out how the invisible platforms worked - at first I thought there was a collision bug in the red platforms.
The difficulty and complexity curve is handled well.
The switching mechanic is good, there is a lot of places you could go with it regarding puzzles and other platforming challenges. A double jump or a booster pack mechanic would expand the possibility space a lot as well, as would a sprint jump.
Always nice to see 3D games in a jam!