I like all these.. hard to choose, lol. I like the alien abductions, maybe muns could submit which pups they'd want taken? But the spaceship idea sounds really cool. I like that one. A couple of the others can be done again, like zombies, or "random." But.. I do have a few other ideas, not sure if they happened here perviously.
Time warp. UTR, the world of it, takes on the appearance of the era down to the last detail. It can be Colonial, Middle Ages, Prohibition, or even the future. Oh! A secondary idea on this.. the world doesn't so much change, as everyone goes back to a past or future version of what UTR was/would be like. As for future, maybe they go to the familiar places that the future pups here came from. Or it can be like 200 years, tho that may be a bit too far.
Moral Compass Reversal. I'd thought on that a while back, though never really saw it done in a game before. Basically, peoples' moral compass goes in reverse. Good is evil, evil is good. Kleptos don't steal. Killers save, while hero types either do very bad things or just have an "any means to stop crime" method. Moral ones become highly immoral. Moralistic folks lose their morals, whereas those without any.. they gain some. Lol.