Graphing Calculator Drawings
Over the course of many dull highschool classes, I taught myself TI-BASIC which is a weird and terrible language, although it does let you manipulate individual pixels of the screen. I made a drawing program that consists of the cursor, which is a single flashing pixel, that can be moved one pixel at a time using the arrow keys, and whose colour can be toggled with the Enter key.
An important part of this program is a series of for-loops that do nothing other than slow the interpreter down enough for the key press speed to roughly match human intuition.
This extremely restricted medium combined with hours of classroom boredom made for some happy artwork.