PokerLich: I was very happy to find this site, I had all these games back in the 90's and was excited to be able to play them again, then I see that Overseer isn't compatible with Windows. Why would Under a Killing Moon and Pandora both be compatible, but Overseer, which is a newer game, isn't?? Not cool, GOG!
Win8.1.1x64 here doing Overseer just fine without a problem. I've had no crashes of any kind so far--which if memory serves is a record with this game dating back to owning it when it was new...;) Game runs better now than it ever did for me then--and then I owned a Creative Labs DVD player the game specifically supported (not needed today with Win8.1x64 or less.)
First thing...relax...just because a game doesn't specifically state "Will run on Win8" doesn't mean it won't, and often with very little trouble (unless the game uses a 16-bit installer and you are running a 64-bit OS, in which case it won't even install. That is *not* the case with Overseer, thankfully.)
There are several threads in this forum dealing with running the game under Win8. If you have 8.1x64 like me then you will need the following version of ffdshow.exe--which replaces the one Gog currently includes with the game:
http://sourceforge.net/projects/ffdshow-tryout/files/Official%20releases/64-bit/
The game really does run much better now under 8.1x64 then it ran for me when it was new and I was running it on expensive proprietary DVD hardware.
--But you raise a fair point...why Gog doesn't state the game runs fine under Win8x64 is beyond me, because it does...!...;)