There is also a 2.5D paradigm. I made a small demo of a 2.5D where I generated pure 2D pixelart sprites and embedded them in a Blender+Unity 3D level. Personally I find this mix very exciting.

Demo: https://acatovic.github.io/afterlight-play/ Tool I used to create 2D sprites: https://github.com/acatovic/ai-game-studio