Users are reporting that Supreme Commander 2, which uses Steamworks as its DRM, will not properly launch through Steam despite being released officially at midnight PST last night.
Users may see a "game is unavailable" error when attempting to launch Chris Taylor's latest RTS. If this is the case, please refer to the following troubleshooting steps:
Supreme Commmander 2 works now after you re-verify your game cache: Right Click "Supreme Commander 2" in your Game Library > Properties > Local files > Verify Integrity of Game Cache > Let it Finish > Launch Game.
I can confirm that this works and that the game is up and running.