Endless Mission Mode
To unlock the Outer Space (Infinite Depth) Level in Mission Mode, you must gather all the characters from the regular stages (hence beating Mission Mode).

Mirror mode time attack
Beat time attack letters A through J to unlock mirror mode.

Mr. Driller Badge
Successfully complete a Mission Driller mode level without using any items or losing a life. The Outer Space level does not have a badge since it is endless.

Unlock Anna
Beat the 1000M level on "Mission Driller" mode.

Unlock Ataru
Beat the 2000M level on "Mission Driller" mode.

Unlock Holzinger-Z
Beat the 800M level on "Mission Driller" mode.

Unlock Puchi
Beat the 500M level on "Mission Driller" mode.

Unlock Taizo
Beat the 1500M level on "Mission Driller" mode.