If you ever played Space Invaders you surely noticed that each time you killed an alien the game went faster. But, if you checked the source code from one of the arcade machines, you would find nothing related to this. That's because this mechanic is a hardware accident. The Intel 8080 CPU had to update every alien. Our machines would do it extremely fast (in fact, it would be impossible to play the original game with current power), but changing the position, redrawing the sprites and checking for collisions for each one of the 55 aliens was really expensive. That's why the game starts slowly, but gets faster, simply because each time you kill an alien, there are less resources to manage. And... people loved this! A simple side effect became an iconic mechanic. The source code (not original one, copyright held by Taito Corporation): computerarcheology.com/Arcad… You can also read about the Intel 8080 here: cpu-collection.de/?l0=co&l1=…