If Steam displays the "preparing to launch the game" message but the game does not want to launch, try logging out of Steam and sign back in.

Unplug any external devices, such as a camera, from your USB ports, please. See if the game launches correctly after that. In addition, try downgrading your video driver version to an older one, as the latest drivers are often incompatible with older games.

Also, make sure your PC meets the game's minimum system requirements, please.

Some types of software and processes on computers are likewise known to be conflicting with games and Steam. Visit Steam's FAQ on interfering programs, please. As suggested by Valve, "even if you do not find any programs that might be causing an issue, please verify your game files and try running the game again".