Long before they got into the Windows scene, Stardock (creators of WindowBlinds and many other cool tools: http://www.stardock.com/) was actually one of the few commercial game development companies developing on top of OS/2.
Galactic Civilizations for OS/2 was their best known release – and while it was a bit rough around the edges from a user interface perspective – the game AI and playability absolutely rocked. The game was aimed to try and take the concepts from the original ‘Civilization’ and extend them to a galactic space faring environment.
This game runs well under Virtual PC – but if you want the midi based music to work you will need to install and configure TiMidity+ under OS/2 (which is no mean feat):
When this game was originally released – I was only able to find one software distributor in Australia that carried it and they were in another state – however I still managed to get a copy. Also of interest is that Stardock has just recently released a new updated version of Galactic Civilizations (this time for Windows) which also runs well inside of Virtual PC.