1. FANTASY Sorcery, demons, monsters, knights in shining armor, magic rings you need to throw into a volcano...
2. FUTURE Technology is rampant. Maybe you have to overthrow your dystopian government or learn how to feel again.
3. SPACE Will you explore the final frontier or are you in a galaxy far far away? Those synthetics don't look very friendly.
4. MODERN Sometimes the scariest things are right outside our front door.
5. SUPERHEROES So you wanna be a superhero? Do you have what it takes to save the day?
6. APOCALYPSE The world's already ended. You're just picking up the pieces.
1. OVERTHROW An evil empire is calling the shots. A corrupt government is making your friends disappear. Fix it.
2. CONSPIRACY No one believes you but your best friend, but things are going wrong and someone in particular is behind it.
3. MEDICAL A disease is killing off people at a horrifying rate and you're trying to find a cure.
4. ZOMBIES Holy shit, is that person EATING someone? You have to escape the zombies, and FAST. Remember: aim for the head.
5. EXPLORATION There's nothing pressing about to kill everything, but you're exploring new territories. Maybe you'll find a new threat.
6. DOWN TIME A break between missions. Heal, regroup, and take care of yourselves.
7. WE NEED WHAT? You're looking for the item to end everything. The BFG, the one ring, the conduit. Whatever it is, you have to find it first.
8. WE MIGHT DIE TOMORROW It's time for the final battle. Are you ready? Are your friends, troops, loved ones? Make your speech or find someone to spend your last night with.
9. MY ARCH NEMESIS You know who the villain is. So does everyone else. They're the Ganon, the Sauron, it doesn't matter. You have to win.
10. THE WORLD WE'RE SAVING HATES US You're trying to save the world but everyone hates you; you're doing it anyway because you need to, it's the right thing to do even if no one cares if you live or die.
11. WE HATE THE WORLD WE'RE SAVING You hate EVERYONE. You hate the world and wish it would go down in flames but you live here too, or you have to because nothing you do to stop trying works. Whatever.
12. WHY WOULD I SAVE IT? You're the villain in any of the above scenarios and then some! Go wild!
As always, these are just suggestions. Make up anything you want, as long as you're having fun!