In the year 2207 a hail of strange meteors strike the Earth, effectively killing an estimated 60% of mankind. Prior to the impact, the nations of the world moved bulks of their populations to space to dodge the coming apocalypse. All but one made this move. Japan decided to ignore the mandate and moved underground, building massive bunkers. Fifty-three years later, mankind returns to the surface, and the struggle for resources of an unprecedented scarcity prompts one of the greatest conflicts in Earth's long history. But will mankind notice the alien passengers that arrived with the meteorites?
These aren't all of what I've done, but they are a good summary. Clockwise we have the rocket impact effect for missiles and rockets, the machine gun impact for lighter guns and cannons, a green beam explosion for drones, and a blue one for NKG units!