[Update Notes]
Now, after satellite technology, not only alien infiltrators but also 'U.F.O' will spawn in Free City. What this means is that a late-game Loyalty Depleted Rebellion can lead to a chain of civilization collapses.

[VeryHotFix(temporary)]
Classified the U.F.O as a Barbarian Recon unit. This change definitely exponentially increases their chances of appearing later in the game!

According to my advice: JUST RUN

[Update Notes]
1. Free city-related adjustments (really you can witness the alien invasion and the establishment of ADVENT)
2. Added Civilopedia for Area 51 and Alien Units