Considering that the record for longest continous submersion of a diesel-electric sub is something like 2 weeks, i highly doubt that 4 weeks in a civilian vessel is achievable
Exactly, I mean you can even add Non-Steam games to Steam. Yes, you don't get achievements that way and there's no support for workshop or big picture or the community plug-in, but you can launch the game from the steam library.
On another note, can Steam, even for a small payment of 2 dollars, add those functions for games not bought in the Steam store, but that could have been bought through Steam? I really want to have TW3 with achievements, but don't want to buy it again.
Tell me you want to get stopped by the police every time you encounter them, without telling me you want to get stopped by the police