Congratulations are in order for the team at Mechanist Games for the successful Greenlighting of City of Steam on Steam Greenlight. City of Steam joins as one of the twenty titles approved in the sixth batch of games to be given the go ahead by Valve to release on the mega-platform. City of Steam is an upcoming browser game built for the UNITY web player and set in an industrial fantasy world with Steampunk elements. Players are able to take control of eleven races of creatures with four classes to choose from.
City of Steam is currently in between beta stages and is set for release sometime before Tupac finishes releasing new albums.
MMO Fallout 
Wait, what?
I am clearly missing something here.
How does a browser game get on Steam?
I can see the benefit for City of Steam in that it gets more notice, but what would I, the end user, get from having it in my Steam library?
According to the Steam page:
If we get Greenlit, what’s in it for you?
-7 extra Pets, with 2 inspired by Valve!
-3 new Steambikes, with 1 Valve tribute model!
-8 new dungeon types.
-Steam Achievements!
-Hats. ALL THE HATS! What we mean is… we’re going to put in a lot more hats.
-Extra hardcore dungeon challenges, tuned to be unbeatable by us.
-Jetpacks. Seriously, JETPACKS!
-Extra character customization options.
Other than that, not a whole lot. Some people prefer a dedicated client, like with RuneScape.