The objective of the game is to remove your opponents' organs using corresponding afflictions before they remove yours. The last person to still have at least one organ is the winner.
 
In addition to Affliction cards (like Pancreatitis, which can be played on either Gallbladder or Pancreas), the game has instant defensive cards, and lots of crazy tactical moves that shake things up. What you end up with is a pretty fast-paced, very fun, and often intense gameplay that's suitable for all levels of players.