So, disconnect from the cloud, enter airplane mode, and shout it from the rooftops (or the subway car):
Unlike digital RTS games, Spartan’s offline systems offer a tactile, deliberate experience: Precision Maneuvering: Games like Firestorm Armada spartan games offline
You’ve found the perfect game, but nothing is worse than launching an only to be met with a "No Internet Connection – Please Retry" pop-up. Here is how to avoid that: So, disconnect from the cloud, enter airplane mode,