They succeeded in destroying the 'queens' of the bugger race, effectively dooming them.
Ender and his peers learn military strategy, space navigation, and engage in increasingly more challenging computer battles against the simulated Bugger fleet - these simulations are the 'games' that the children play.
Anyone who's played a Castlevania game remembers the Belmont, the cursed blood-lineage that has the power to hunt and defeat Dracula even though the pesky bugger keeps on reappearing throughout history.
