I think that game developers just need to moderate how much their game writes to the blockchain. HIVE excels at storing JSON data, but since the storage and data replication is decentralized, you wouldn't want to write a game that records every step that a player makes to the blockchain; that wouldn't scale well. I think a performant FPS or RPG could do well on HIVE, as long as most of the processing is done on the client's computer or centralized servers, and it is judicious in writing only necessary data periodically to the blockchain.