Sprites can give the illusion of 3d depth by stacking up multiple planes and putting them slightly out of sync with each other either spatially or temporally. This is a single sprite.
Multiple sprites with different alphas give the illusion of depth.
Sub-frame delay between sprites amplifies the depth and follow-thru.
Actual 3d depth is minimal
You can do it with landscapes too. The layers translate values increase to reflect their apparent height. Hard split-lines between layers creates the spatial aliasing.
Normal 2d scrolling.
Multiplane scrolling 4 layers of depth with soft splits between. Layers are better integrated, but occlusion artifacts become visible.
3DCGI 