I was wondering how people are dealing with players being able to lean through objects/walls & their colliders in Unity? Any help, suggestions or code snippets would be highly appreciated.
Putting collision on the head that is blocked by geometry is a bad idea, though you can try to detect these cases and fade the screen to black or otherwise put some sort of warning message.
In the game Dimensional, if you put your head through a wall for over a couple of seconds, it kills your character, and you start back from the last checkpoint. I don't know what game engine they made it in, but that is how they deal with it.