The forum

I did some searching first to see if anyone was able to Run City of Steam in Linux and didn't find very much.
In fact they claimed to create a Linux client with Unity Player, but I still don't see it available on Steam or their website.

I checked WineHQ's and there isn't even an entry for City of Steam... how strange is that?
Its a pretty popular free-to-play MMORPG

Anyways, thought I would try it with Pipelight because  Dead Frontier worked perfectly in Pipelight

and...

It runs!  I was able to play in Mint 17.2 64-bit on my GeForce 7600 GT
Next I will test at home on my GeForce 550 Ti with all the eye-candy on HIGH