One pitch a day: in August of 2011, I dedicate twenty minutes each day to writing an "elevator pitch" for a story or a game.
This "murder party" takes place in 2873. Humankind has ceased to grow in numbers: having kids is out of fashion and people mostly do not die anymore, barring the rare freak accident. A consequence of this situation is that souls in Paradise cannot reincarnate as freely as before. As the waiting gets longer, morale is at an all-time low among souls who want to make a comeback on the karmic wheel or are just dead bored. Pun intended.
The players' characters are souls of dead people, famous and infamous, who hail from all continents and all eras. They have all applied to be reincarnated in a new man soon to be born. Only the characters of the players remain in Paradise. They must convince the judge to pick them for reincarnation, or else they might very well have to wait millenia for a new chance at life.
Then something ugly and almost unheard of in Paradise happens to the most promising soul. The judge is at a loss. He cannot allow a rotten soul to infect a newborn person and he does not know who is responsible of whatever happened to the nice soul. He demands that the candidates lead the investigation and unmask the miscreant soul.
To find out the truth and accomplish their personal goals, characters can use all kinds of powers depending on their soul's past lives. At the end of the game, whoever scores the most for the judge is allowed back into the world of the living.
The judge has a swell soul. Oh, and he used to be [insert name of your favorite historical villain] and later [your best friend] back then.