Should you happen to have an HP7440A or similar plotter hanging around, you could have a quick game of Flappy Bird — or Plotty Bird as [WesleyAC] calls it. Just be sure you have some blank paper. The whole thing fits in about 200 lines of Rust code and — according to the author — gets to about 20 frames per second.
Watching the thing go, it appears that it draws a random set of pipes and then traces your flight path on the same page in real time.
Of course, this isn’t very practical, but we love the idea and watching a plotter go is second only to watching a 3D printer. Of course, you could do a similar stunt with a 3D printer and a pen mounted to it if you rewrote the code to use GCode. The code is short enough and clear enough, too, that it wouldn’t be a bad excuse to learn more about Rust if you were so inclined.
If you want to understand the code or change it, you’ll probably find an HPGL reference handy. The format is very simple: two characters, arguments typically separated by commas or carriage returns, and semicolons ending the packet.