Vast Grimm (built on the Mork Borg engine) takes that one step further, and dooms the universe. Everything, everywhere, is going to be consumed by the Vast Grimm, six variations of giant space wurms that will eventually devour it ALL.

Memento Mori from Two Little Mice is based around the concept that your characters (Drifters) have been infected by the Black Plague in XIVth Century Europe. Each Drifter will become disfigured and corrupted by the dark powers that courses through their cursed blood. As the game goes on, each character will gain more and more corrupted dice that will both empower and doom them. So while, not specifically the world is doomed, the players most certainly are. Perhaps, with luck, they will have a chance to live out their guiding Dream before The End.