I've managed to get Spiral Knights running properly in Steam using Wine, but there's no sound. Sound works in other Wine apps (including Steam itself) and the native web client works with sound, so I don't think its a problem with either SK or Wine.
I think it might have something to do with Java running under Wine, but I haven't found any way to get it working. Has anyone else managed to solve the problem?
Btw if you want to get SK running at all under Linux you need to use Java 1.6. Last I checked 1.7 won't work. (Arch users can install the jre6 package from the AUR)