If you are of a certain age, you likely played Commander Keen. Cane’s run in the video embedded below was a world record at the time, but has since been beaten in a near flawless run by CapnClever. Even so, I like this video because of the amusing running commentary and chat that is conducted during game play. (There are some expletives, so any children watching might need to cover their parents’ ears.) The ‘death exit’ at the beginning of the second level is a glitch in which the player can allow Keen to die at the edge of the game’s map and then immediately save and reload to complete the level.