Computer games are softwares themselves. The types of games vary. Some install direct to the hard drive while other run off of a cd or you log onto a game server for online game play. Software engineers and designers spend countless hours developing game maps, characters, objects seen in the games, and programming codes depending on operating system(s) intended for. While some things in games use the same standards for OSs, video, sound, each one has it's own design builtin.