I just got this as part of the Goodie pack and it WORKS FINE on my Win10 64-bit laptop. I had to be a little patient at the Prepare for Battle screen but didn't wait long for the battle to commence. It's on old game and it's been years since I played so the interface - especially without pop-up labels - will take some re-learning but once there I expect this to be as fun as it always was. Falls into the same category as "Final Liberation" for me. They are old but still hold up as enjoyably bringing the tabletop games to life on my screen.
OMG, prayers are indeed answered. I woke up this morning determined to check in with GOG to see if there was a timeline for this game to make it into the collection (#1 on my GOG wishlist of not-yet acquired games), opened GOG, and behold, there it sat on the splash page. Made my day. This is the only game I've ever encountered that hit the full richness of science-fiction 4X from space battles to ground warfare and planetary submission, to individual leaders, to factions, to xenos to supply. Sure it's a hex-based boardgame-like but none of that mattered in any of immersion into this world. It's not perfect and it's not fast and it's not flashy but it's rich and rewarding. I am writing this based on my original playing of the game. I will update this after I've played the GOG download version.