Jetpac

Jetpac is a ZX Spectrum game that is made playable in Donkey Kong 64 as a test by Cranky Kong in his lab. In the game, the player plays as an astronaut trying to repair his space ship. The astronaut has to collect all the pieces for his ship and fuel while blasting aliens with his laser gun. The "Jetpac" game is an actual real world game that was the first creation of Rare, at the time of its release known as Ultimate Play the Game. Rare decided to put this game in Donkey Kong 64.

Rare updated and re-released the game on Xbox Live Arcade as Jetpac Refuelled. They also re-released the game and it's remake on Xbox One as part of Rare Replay.