UFO: Aftermath (2003)

During the Twilight, all human responses were futile. Choosing caution over aggression, the governments of the world didn't realize how quickly the end could come, and were buried alongside those that they governed. A few, however, did survive, sealed in underground bases with stocks of food and oxygen. After several weeks, the spores seemed to have disintegrated, decomposing and settling into the soil. The world seemed safe again, for a time. This is where you come in: you must gather together the remaining peoples of the planet, find out what has happened, and, if possible, get your revenge.