Mothership Zeta abducts the player to the titular spaceship, chock full of hostile aliens and their robotic servants. For the next 3-10 hours (depending on how many times you have to reload to have not messed up the fetch quest achievement) you'll be running around both inside and outside, stopping the invasion of Earth by outside forces. Oh, and stealing all their cool tech. And meeting a samurai!
They say "save the best for last". Nobody told Bethesda it seems. This is pretty much as awful as many complained Operation Anchorage was, but adds something even more annoying: a fetch quest achievement that relies on you not missing anything along the way. Yep, you guessed it, parts cannot be returned to, and these parts contain precious audio logs. Everything looks samey, you'll never really switch guns after getting the alien rifle, the loot's nothing special, and the missions are pretty dull. Not much fun at all.
Achievement-wise, it's the usual 3 quest ones and a final, "bugger this for a lark" fetch quest.
