I love this mechanic in my platformers! World/platform swapping is always fun to jump around in.

Level design is well done overall with no challenge leaving me feeling that it was unfair.

Movement felt a bit too slow or floaty at first, but after playing for a little bit it felt natural and worked well.

Light and dark are used in creative ways such as hiding platforms, dissolving platforms, changing the player's visibility, which contributed well to the theme of contrasting the two.

My only real complaint is that I wished the switch key was bound to something easier to press while I was holding right. It's not a big issue and is only a little uncomfortable. 

Overall a fun experience and a decent platformer made within the time constraints.