I realize there is only one background layer, but what is the best way to fake having multiple? how can I have some hill objects with slightly higher “parallax” than the sky and clouds background?
There is no way to do this without building a behavior for it.
You could have the clouds in the actually aground layer and then have the mountains in the game world layer, then give them some kind of behavior that mimics it.
The main way I can think of doing this would be by extracting the players X velocity and then having the mountains move at (the players X)*0.5 or something like that. I’m not sure that exactly would work but you probably need to do something like that.