Video game clone grouped as "Myst clones". Some video game genres are founded by archetypal games of which all subsequent similar games are considered derivatives; notably, early first-person shooters were often called ""Doom" clones", while the success of the open-world formula in "Grand Theft Auto" led to the genre of GTA clones. The genre of endless runners is based on the success and simplicity of the game "Canabalt". In these cases, games that are "clones" of another are generally not implied to have committed any intellectual property infractions, and otherwise considered legally acceptable practices, although calling such games clones is generally considered derogatory.
Penumbra (video game series) Penumbra (video game series) Penumbra is the name of an episodic survival horror video game series developed by Frictional Games and published by Paradox Interactive and Lexicon Entertainment. The games use the HPL Engine 1, initially developed as a tech demo. "Penumbra" is notable for its horror styling and for allowing advanced physical interaction with the game environment. Set in the year 2001, "Penumbra: Overture" follows the story of Philip, a thirty-year-old physicist whose mother recently died. After receiving a mysterious letter from his supposedly dead father, Philip follows a series of clues that lead him to a mysterious location