Gotham City Impostors Is F2P on steam
 

The game is going free to play on steam the game for windows live will now be no longer be officially supported :( http://forums.steampowered.com/forum....php?t=2915631

F2P on Steam
http://store.steampowered.com/app/206210/

does this include the original achievements?

I don't thinks so. It will have steam achievements

Microsoft recently announced that they're allowing F2P games (at last) on their console and since this is not F2P, we could end up seeing it very soon. I assume everyone who's already bought it has been compensated with their free hat.

Is it possible to buy the GFWL anywhere?

Hmm we get a permanent double xp boost :s

Yes, you have to buy it from the GFWL marketplace rather than Steam now.

Is there a way I can re-download the GFWL version if I bought the game off Steam? Or do I have to buy it again?

You have to buy the game again, unfortunately the steam version is entirely different from the GFWL version now, i finished this game via Steam on launch but when i load it up now all i get is a sort of "Team fortress" like game, so there for, if you wish to complete this now you'll have to re-download it from GFWL market place. Good luck.