Down load the Spiral Knights Game directly from the webpage, sync your account to your facebook, and then use the SK you just downloaded and log on using your facebook, viola, when Steam lets you down there is a solution.
Link your steam account to your facebook, have facebook openn in the browser when you open non steam spiral knights click the facebook button to log on as a steam knight
This worked for me hopefully it will help others.
What if we don't have a Facebook account? And what does a viola have to do with this? Isn't that a musical instrument?