Actually, many games do that. I was scared too, but if the game is just inspired by another without using the real game's name, with an EULA stating all rights of both developers, the game can be released as a 'parody' and sold. However, if the owners of the references feel harmed in any way, they can ask for the removal of any reference and mention of the original work without any lawsuits or anything.
(companies are usually okay with sold fan games, but never mess with Nintendo and Paramount.)