Could be, but IMHO it wouldn’t be worth it. I mean, you could use it as a network layer and run game loop in NIF or port, but as network isn’t the most problematic layer of such game you can use any other library to handle that directly in language you will be using as a game-loop. So I wouldn’t say that this is totally unusable in such case, but I wouldn’t say that you would get much advantages of using BEAM there as there is not that much benefits.
So as component - yes. As a whole system - no.
There are companies that are providing MMO capabilities for games and are using Erlang, for example https://demonware.net.
