The Atari 2600 version of Mr. Run and Jump originally began as a homebrew project by programmer John Mikula at Graphite Lab before being developed into the modern version. It is a simplified but significantly more challenging game that contains 7 color-coded levels (blue, green, yellow, purple, red, white, and black with invisible platforms), each consisting of single-screen left-to-right maps connected by ladders. Controls are simplified compared to the modern version, with just joystick movement and a single jump button. Checkpoints only appear at the start of each level, making completion much more difficult than the modern version.