Unlockable stages:
To unlock five bonus stages, earn 25 gold trophies.

Secret stages:
To unlock 14 secret stages, collect the 45 Green Crystals. There is one Green Crystal in each regular stage. Also, to unlock a 15th stage, beat all five bonus stages.

20 Balls:
To unlock 20 balls, beat all 45 stages and the 15 secret stages.

All music:
To unlock all music, beat all the stages.

Mirror mode
To unlock Mirror mode, beat all 45 stages.

Unlockable Balls:
Unlock the following Balls by performing the corresponding tasks:

BALL – HOW TO UNLOCK
Car Crush Ball – Beat the first Mirror mode stage and collect the Yellow Gem.
Flash Ball – Beat the last Normal mode stage and collect the Yellow Gem.
Galaxy Ball – Beat the first Night Zone stage and collect the Yellow Gem.
UFO Ball – Beat the last Mirror mode stage and collect the Yellow Gem.

100% game completion:
To achieve 100% game completion, beat all regular, bonus and secret stages in standard and Mirror modes, and unlock all Balls and music.

Green Crystals hint:
Every green crystal is either hidden, hard to get, or both.