Arcanum from Steam doesn't work with Windows 8.1

A couple of years ago I tried playing Arcanum again. I downloaded the game off Steam and tried playing it on Windows 8.1. I had major problems with lag that would always get progessively worse. It made the game unplayable. I tried lowering screen resolution, I tired running on Compatibility mode (XP and othe older versions of Windows) and nothing ever worked. However I forgot to post my question here, maybe someone here can give me some solid advice.

Any tips if I want to try again?

Thanks,

Rob