Sprite stacking
Fakes 3D in a 2D engine by stacking many top-down sprite slices with a small vertical offset and rotating them together.
Each slice is a horizontal cross-section of the object, like the layers of a CT scan. Drawn from the bottom up with a few pixels of offset, all rotated to the same angle, the stack reads as a solid body seen at an angle — and rotating the whole stack turns the object. The technique is cheap and popular in indie games and on platforms like PICO-8, where it gives cars, houses and towers volume without a single polygon.
The slices are effectively voxel layers, so the method is kin to voxel models. The drawbacks show at steep angles, where the layers gap open, and in draw cost: a stack is a lot of sprites.