The game started beautifully after installing, it loaded quickly and instantly. Now I tried running it and it staled. Black screen made me hibernate several times to recover control. Then it would display a green central square only. Tried reinstalling but got the same behavior. Only other game installed after testing this one was Heretic Kingdoms, which also runs perfectly. I tried adding administrator priviledges and Windows 8 compatibility, to no effect. So I ended closing wifi completely short of airplane mode and it finally run! Albeit taking longer to display the screen, unlike after first install when it instantly. I tried again with wifi connected and I get the same black screen behavior. Memory is relatively free. It run with the browser on but unconnected, so it is not conflict with running applications. I am still to see if I can recover the save file from the previous installation. So does wifi has to be completely off and even disabled to run or is it known behavior glitches with this game?

I have wi-fi connection and KB runs perfectly, no conflicts. Win7, x64.

... but I mean running it without wifi, I do not want it to connect anywhere while I play but it seems it was expecting wifi open to run.

That's strange as I never have wifi or any internet related stuff running when playing any of the KB games.

Just an idea, have you tried restarting a new game as it worked originally so maybe a save game has become corrupted. Another thought, have you run a complete scan on your computer - both a virus check and Malwarebytes?

Those never work, but I may try checksumming my installation and a newly downloaded installation. I m freaked out since I could not find a big game in my computer, unfortunately not from Gog, seemingly...