Basically I would simulate a Z depth for every object with an instance variable that starts at 0 (farthest away) and gradually increases. This Z would be used as a multiplier for size so it looks like objects get bigger as they get closer to you, as well as a modifier for position. It would also be used to set conditions for collisions, such as if the player and object are around the same depth.
Sorry I don't have an example or actual numbers, the math is beyond me to put together quickly.
Thanks, yes I have similar thoughts about it.
Anyway it would be great if someone can share any sketches devoted to this theme.