Thank you!
Still today I load up the game just to play with the coin, I really love, how it works. For me it still feels a bit off, so if I'll work later on it, I'll make it's own physics, not the Unity based one.
Mid-air flip was in the pipeline, but did not have time to do it. I was thinking about right click to slow down time for 5 seconds, and during that one more flip can be done.
For the 3rd level a hint: if you land on the first night or day platform, from there it is easy to go up. You just need to have a small velocity flip to the middle of the next platform, with just enough height. With that the coin will turn alway only 2 times, and land on the same side as it was ;)