Artworks made with pseudo 3d algorithms (algorithms which fake perspective or which use special cases to give artworks some depth) such as layers stacking, fake raycasting, shapes shadow, tunnels. Some of them can be done in less than 256 bytes.
Tunnels made with dots, lines or polygons.
Those started as a cartesian way to draw circles made of blocks then expanded by adding more, applying a colormap then a second texture (for the first ones) which is used as a mask to display the text and then day/night cycle from a mask. I quite like this effect as it look like some futuristic glitchy billboard by varying the blocks size.
Can also make some pseudo metaballs with modulations.
Simple 3D objects with lighting and 2D shapes drawn over using brightness data. The cube is interesting as it look like the faces are dislocated. The last video is an advanced version made with different shapes, the 3d scene consist of a simple cube and a sphere.