Casual gaming's biggest star, Flo--unlike, say, Halo's faceless super soldier, Master Chief--is a recognizable character with a recognizable problem: She's got to keep her diner running.
None more so than its first release, the monumental game known as Halo, which pits a Marine named Master Chief against an alien horde called the Covenant.
Halo used regenerating shields to ensure that the player could throw Master Chief headlong into any obstacle without fear of breaking their game or eliminating hours of progress.