One of the main concerns for current game developers include how easy it is to set things up, conversion rates, and how much fees it'll cut. With BTC current fees I don't think it'll be easy to convince developers of using BTC payment, however it'll be relatively easier to use other crypto that have lower fees.
As for how easy to implement, I guess if you create a Unity/Unreal SDK along with other SDK for well known game engines, it'll give things head start.
This makes it ripe for an ecosystem token, similar to purchasing gems, coins, what have you. Is anyone doing this currently?