You're about to have one of those days ...
Aliens have launched an all-out offensive against your space ship. They are sneaking in through an air shaft and you're going to have to stop them.
The aliens attack in groups of three. Be careful how you take them out. One is harmless and poses no real threat. If you take out the True bad guy, the others will be disarmed. But if you make a False move, and shoot the wrong alien at the start, you're in for pain and misery. So choose your targets wisely.
Now, go save your ship!