Instructions
Launch Steam, and sign into your user account.
Click the "Library" menu tab, then launch "Space Empires V." You must play "Space Empires V" at least one time while connected to the Steam network before being able to play it offline.
Close "Space Empires V."
Click the "Settings" menu in Steam, and ensure "Don't save account credentials on this computer" is not enabled.
Click the "Steam" drop-down menu, and click "Go Offline."
Click the "Restart in Offline Mode" button.
Click the "Library" tab.
Click "Space Empires V," and click "Play Now."