The classic version offers a standard free spins round, while the Gold edition offers a collection bonus as well where collecting the Gold Buffalo will turn symbols into the jackpot symbol for the remainder of the free spins. The scatters are the gold coin and 3 or more of these will award you with free spins.
All of the versions are All Ways and come with scatters on all reels. Buffalo has come to us in many incarnations including the Gold slot which comes with wild multipliers, a giant version, and a classic version.