i have many ideas, im still working my way around the engine so it would be cool to see some more experienced users executing these in a much better way then i can at the moment
Classic doom style: 3D world, but 2D sprites for everything else
Quake style: absolutely no 2D, everything is modeled with 3D and animated
3D building: given a number of shapes and a pregenerated world, with the ability to place the objects following a strict measurement system
2D building: something similar to terraria, with pixel-art style textures and creative gameplay