Sure, but it becomes a question of how far you can push things. Maybe you raytrace the whole thing. Maybe there's some fractal geometry going on. Maybe you use a fisheye lens projection. Maybe your levels are dynamically tesselated. Maybe you have to do a few fancy tricks to achieve equivalent texturing etc.

But ignoring the GPU you have on your system is boring

Writing a retro-inspired game using retro approaches despite all the modern options is precisely what makes this interesting.