After killing the Swirl in mid-flight, a black vertical line appears across the spot where the Swirl was shot. This line is referred to under the Helpful Hints section in the game's manual as the "Ghost of Yars" and warns the player to stay off its "mean streak". If the Yar is in the lower third of the screen and the black spot on its back is aligned across the vertical line at the moment the explosion vanishes, the game ends and goes into the "Game Select" screen with "HSWWSH" in place of the player's score. These are the mirrored initials of the game's creator Howard Scott Warshaw.

The fly species in Yars' Revenge, the yar, and their home planet, Razak, are reversals of then-Atari CEO Ray Kassar's name. Creator Howard Scott Warshaw told a marketing executive this was the name's origin, but did not inform them that Kassar was unaware of the name's origins, leading them to believe the name was coined by Kassar and preventing them from informing him and getting the name changed.