Something that always felt weird to me about XCOM (the new one), was that when the aliens attacked, you could only ever defend one area.
On the one hand, this is a fun mechanic because it gives the strategic part of the game a sense of urgency: the enemy will slowly advance against you until you defeat them, so time is of the essence. On the other, it can be frustrating as a player because the regions which are attacked are random, and you cannot save all of them.
MASSIVE CHALICE borrowed this mechanic as well. When the Cadence advances, it typically will target two or possibly three regions for corruption. Each of the game’s ten regions can be corrupted three times before falling (literally, the pieces of the nation drop off the map when fully corrupted). However, successfully defending will also lower the corruption in the region by one. Because of this, it’s in your best interest to defend regions that have a little corruption, to limit the overall growth of the Cadence.
Because you can only ever defend one area you have to choose. As the game continues, the choices become more and more dire. Do I want to lose this Keep and forever lose that bloodline? Am I willing to part with a crucible? Do I really need a second sagewrights guild?
I hope you enjoy my defense of the Gisling lands. Being my most powerful family, I decided they must be protected at all costs.