Faceless, previously known as Slender: Source, has been blocked by Valve on Steam. The game has so far failed to make its debut on Steam due to copyright issues. Faceless features the “Slender man” as the main character. According to Justin Ross, developer of Faceless, he has acquired permission from the creator of the meme to use “Slender man” in his game.
However, Valve has not given the green light to the Faceless because they say an unknown third party holds an option on the “Slender man” character despite its open-source origins. Valve reckons that the developers of the Faceless need to get permission from this unknown third party too.
Justin Ross says that he has asked the option holders for permission, but so far they have failed to reply. If Valve does not release his game on their distribution service, he will simply launch through ModDB.
One cannot fault Valve for trying to avoid a lawsuit, but I do hope this game is released soon because its looks promising.