I’m far from experienced Unity dev but i finally managed to recreate one of the most unique games mechanics I’ve seen. My inspiration comes from a game Legend Of Zelda: Link Between Worlds, where Link could become a “painting” and walk right on wall to avoid obsticles - Wall Merge. I’ve never seen anything like that before and always thought about implementing it.
To create it I used Decal Projector and raycast. Wall Projector is attached to a gameobject that is inside a wall, while raycast checks the wall and tells when gameobject is supposed to rotate when he hits the normal with other rotation. It’s not a perfect implimentation but I’m still learning! 
If you wanna support it, please play a short demo I’ve created and if you can, leave a comment there!