Asteroids is an unusual video game. The 1979 arcade classic uses vector graphics instead of bitmaps. Vectors are lines, which are generated on a TV screen by magnetically moving the CRT (Cathode Ray Tube) and blasting a stream of electrons at particular points, painting glowing white lines on the black screen.
Using this vector-drawing technique, Asteroids created a distinctive look. It's also relatively hard to emulate because the physical display technology is tied to how the game looks—in areas where the electron beam lingers, images are brighter than areas the tube just zips by. It's also an extremely crisp, precise style of line art that's simply hard to draw on low-resolution bitmap displays.
In the video below, mathematician Matt Parker visits an arcade where programmer/artist Seb Lee-Delisle shows off his version of Asteroids using a giant 4-watt laser. The pair discuss how the original arcade game worked, and then explore Seb's modern laser version. Although this video is 17 minutes long, it goes by in a nerdy flash. Enjoy: