There are the usual candidates, Unreal and Unity; perhaps Lumberyard and Cryengine deserve another look? or how about … Excel?

Inspired by a computer science teacher who once said that “a given computation can be achieved with any programming language, even spreadsheet formula” that’s just what C Bel has done.

Doom.xls is a 3D game created using only Excel formulae that is capable of generating an infinite number of procedural mazes with real time ray-traced rendering, occlusion calculation and more.

 You can read more about this unusual project on Gamasutra’s website where you’ll also find the source files and an example video.