I'm really glad that you liked it ! Also, you do raise some good points.
Actually, I didn't use Unity's physics library to handle the character's behaviour, since it is not easily fine-tuned for a fluid platformer gameplay, especially one that diverges from standard gravity. That means I resorted to coding a character controller from scratch, using lower level functions for collision detection, resulting in some problematic edge cases when a platform's dimensions didn't allow it to follow the planet's curvature closely enough. All of this would still require a whole lot of polishing.
I also wholeheartedly agree with your second issue. This one could probably be solved by tweaking the shader I used for most platforms, and more importantly by giving the player more control over camera movement.
I hope you'll be able to play a more polished version in a not-too-distant future.