Myst is a puzzle-solving point-and-click game that was originally released for the Macintosh. The version shown in this run is a homebrew demake for the Atari 2600. Due to the significant technical limitations of the Atari 2600, the entire game wasn't able to ported over. Only enough of the game was implemented that the result can be considered "complete and beatable".

Spikestuff nevertheless marches on and beats the game in record time.

You can get the game here.