Someone always points out how Doom wasn't "real 3D" like it's some sort of gotcha. Games are smoke and mirrors, it's all a 2D grid of pixels at the end.
Well yeah, a 2d grid of pixels also describes the result of rendering a 2d game. It matters how you arrive at that 2d grid of pixels, that's why you can't render Crysis on just a CPU. At least not in real time.
