If your game farm is a business, charging customers to hunt, I believe each state has regulations that outline land size et al. South Dakota has quite a lengthy posting on their hunting web site. Not sure about other states...
You can raise a lot of quail in a flight-pen of about 16-20' across, and around 100' long. For pheasants if you are breeding or flight training you need a lot od space, around 8'x8' per bird. otherwise they fight.