Some PC users are experiencing this issue and a majority are facing the problem where the game has been downloaded but, the game is not playable. The reason behind this is that the game is unpacking and depending on your system the game could take a lot of time.
As for those players whose downloading is stuck at one point, make sure you have some extra space on the drive to unpack the game otherwise the download will remain stuck. If you preloaded the game, try restarting steam and the game will unlock to be played.
Once it does that, the game must be decrypted. Steam preloads the game in an encrypted format on a per-user basis. As such it;
1) Confirms you own the game.
2) Scans for any updates required.
3) Begins decryption of the game files.
It may ‘look’ like the game download is stalling. But in fact, it is decrypting your preload files. How long this takes depends on your CPU speed and your disk IO. Please be patient while the process finishes.