YOU CAN PLAY FROM WEB BROWSER WITH STEAM.

(Contrary to popular belief)

How to:
1. Logout from Spiralknights.com. Make sure you are NOT logged into your Steam, or an alt, etc. (If you're logged in onto Steam, "Play Now" won't work)
2. Click the "Play Now", will redirect you to an .xhtml page.
3. Once you've reached Login Screen in Spiral Knights Client, click "Login through Facebook".
4. This will redirect you to a website page, where you can choose to either login through regular means, Facebook, OR A STEAM ACCOUNT
5. Once you've logged in, a message that states that you've logged in, and that you should return to the game will appear
6. Return to client.
7. Continue standing around in Haven unproductively.

And that should work.

Feedback below, let me know if it works for you, etc.
It's worked for my main, and for a few friends I've told.
So it should work for you! <3