Donkey Kong Country Returns: How to Unlock Bonus Levels
In Donkey Kong Country Returns for the Wii, there are a total of eight bonus levels you can unlock in the game, one for each world.
Every level in a world (besides boss levels) contain hidden K O N G letters you can collect. If you collect all of these letter in every level in a world, you’ll unlock that worlds bonus level.
Once you beat each bonus level, you’ll receive a red orb for that bonus level. Collecting all eight red orbs will unlock the hidden World 9: The Golden Temple.