Z-Slices

Z-slices are a sub-style of the 2.5D styles.

Z-Slices are like layers of a cake. Each sprite of an object is stacked and offset. Giving the allusion its 3D. http://www.like100bears.com/writing/2d-3d-in-gamemaker-studio

https://www.youtube.com/watch?v=_BztMPC5Kk4