Pandora

The generation ship Pandora has been set to infect the Earth with a nasty spore of deadly flowers. You have to stop this ship with the help of all the people on board that are still alive. The only person that can stop the ship is you. When you arrive, you have to get ID from the entry officer, or else you get frazzled by a roof lazer. The time limit to destroy this ship before it begins infesting the Earth with spores is 999 seconds.