As of now we know of two people who cannot run Spiral Knights on Windows 10 over Steam.
[Thread 1] [Thread 2]
I don't ask for an instant fix, because there may be changes to Windows 10 in the near future due to it just being released, but please look into the problem and let us now what your approach will be.
/salute
If anybody else has a problem with Windows 10 regarding Spiral Knights, please explain it here, so we can collect data
Works for me in Windows 10/Steam, I wasn't recording though
However, some video cards are no longer supported.
http://wiki.spiralknights.com/Technical_issues_FAQ#Windows_10_Help
like he said in that thread, he has an Intel chipset that is older than the HD 2000.