[UPDATE] A Konami representative said on Twitter that the bug preventing users from playing offline should now be fixed. All new PC downloads of Metal Gear Rising: Revengeance should work without issue, while those who already downloaded the game will find that the buggy files have been replaced.
The original story is below.
The PC version of Metal Gear Rising: Revengeance is currently suffering from a bug that requires players to be connected to the Internet for the game to function. This isn't how the game is supposed to work, and a fix is on the way, Konami confirmed earlier today.
"OK. Getting to the bottom of offline play. It is a bug. It is not supposed to work like that," PlatinumGames creative producer J.P. Kellams said on Twitter. "We are working on a fix and will update soon."
Separately, the official Konami Twitter account released this statement: "We are aware of the offline play issue for Metal Gear Rising for Steam and are working on a fix. Please stay tuned for more updates!"
Immediately following the release of Metal Gear Rising: Revengeance for the PC yesterday, users revealed that the game would not function whatsoever in Steam's offline mode. In addition, if you lose your connection mid-play, you'll be disconnected from the game.
We'll update this story when Konami has more to say about the upcoming fix.