In Opera Omnia you play a government historian who has to come up with convenient theories about migration in the past (of their own people and “the others”, a separate people). The story takes place in dialogue between the player and his politician friend.
The gameplay may be a bit hard to “get” at first: basically, you have to think backwards: if people were in this city during a plague, and if famines reduce population, that means that they had to have had a lot of people in order to survive that plague: thus, famines actually increase population if you work backwards in time.
The challenge of each level is that you’re given something to prove by your friend – such as prove that 300,000 people lived in this city a long time ago – and you adjust migration patterns that will show how 300,000 people could have lived in that city a long time ago. Gradually you realize that you’ve been helping prove truths which have political import…
This game is really one of the most inventive and impressive indie games I’ve played in quite a while. I do wish it were more polished and had nicer art, but even as it is right now it’s a masterpiece. - rinkuhero