The windows version sounds OK (some people actually have problems with 8.0 that can be fixed upgrading to 8.1).
Your graphics card certainly sounds new enough (it can handle the shaders and directx stuff it needs to). Have you tried doing a clean install of the latest graphics drivers from the AMD website? This link seems to be the right one for your card. Sometimes automatic installers cause problems with a graphics driver install that lead to the game not working. Sometimes its just that the drivers are a little old.
The third common possibility is with various programs that interfere with Stonehearth. The user interface of the game is displayed through a Chrome browser interface and some programs are designed to hook into that (anti-virus or web-protect software commonly does). There is a big (but not exhaustive!) list of such programs here. If you have one such program, you’ll have to disable it to run Stonehearth for now. They are looking into ways to fix that.
If neither of those things seem to be the case, there is still some things we can look at.