Handmade 2D game and engine. This is currently my main project. Source code is here.
Spinning transparent cube in C and OpenGL. Ported to multiple platforms including WASM and WebGL. Source code is here.
Spell words with the elemental symbols from the periodic table ("He", "Cu", etc).
Pseudo 3D tunnel renderer.
A simple texture is transformed based on each pixel's distance and angle from the center.