I make no apologies for mentioning Puls because I think it's a really impressive bit of programming (in assembly) and it was originally written in C. It uses no 3D libraries or hardware acceleration. Puls is a Binary-search raycasting of an animated 3D scene and is just 256 bytes long. You can watch a demo video of it if you don't want to run a dos cmd line program on your PC. There are also Windows versions but they're normal size exes!
Jan Kadlec (aka Řrřola), the developer of Puls has published a lot of useful C code for graphical transformations and even a simple Wolfenstein type game.
Back in the 1980s there existed a demo scene where programmers produced scores of highly impressive demos of what they could get a computer to do. It was usually but not always a CBM-64. I never took part in that scene but did manage to get 24 hardware sprites on screen in a game at once (the hardware only supported 8 sprites but you could set an interrupt to occur down the screen on a scan line and reposition them).
There is still a demo scene now and most of it is in assembler, hence usually off-topic for here but irrespective of programming language, you can't but be amazed by Puls and it's worth reading a detailed explanation of how Puls works written by Michael Birken whose site you might also enjoy for this ASCII game written in C#.
- Link to C# Game Code Library
Back in the 80s?
See http://www.scene.org