We've had several cases of people with your problem who resolved it by disabling VPN or firewall. The game files are located on Google Drive, and if you're using VPN, Google might think you're an "uncertified" user and restrict access. The game files get downloaded to The Fertile Crescent_Data, so if there's nothing there, it means the launcher wasn't able to fetch the game files.
In the distant future, we'll probably release the game on Steam, and then not have the current launcher anymore. But for now it's very useful since it makes it easier for us to patch the game, and you don't have to manually download (and check for) the latest version. :)