From Wizards of the Coast, it's "The revolutionary card game where you win by getting a head."
The game takes place during the French Revolution. Players are rival guillotine operators, collecting the heads of the Paris nobles. Nobles are worth different point values (Marie Antoinette is worth 5, but the lowly Piss Boy is only worth 1.)
The Disneyesque art belies the grim theme. It's got some historical accuracy, too - beheading Robespierre ends the game.
It's a very simple variant of Magic: the Gathering that can be learned quickly, but the many "action cards" that reorder the nobles keep the game fresh after repeated playing. I recommend it!