Where did you buy it from?
If you got it from Steam, maybe it's downloading more updates.
As for requirements, pay special attention to the video card. This is a more demanding game than most current adventure games, and if you have only minimum spec for video card, you'll probably have to turn down settings to minimum in the game options.
If you need more help, please list your specs,
RAM (system memory)
Windows version needs to be 7, 8.1, or 10 and may have to be 64-bit Windows