Unlockable Stages and Masks
Unlocks all save automatically. The Kirby, Waddle Dee, and Meta Knight masks will permanently unlock once you go to the level select screen while you have StreetPass for Kirby: Triple Deluxe turned on (there does not need to be any pending interactions, it just needs to be enabled).
Unlockable: --- How to Unlock:
Dedede's Metal Mask --- Complete all Normal Stages.
Kirby, Waddle Dee, & Meta Knight Masks --- Load the game up while having Kirby: Triple Deluxe's StreetPass data installed on your 3DS.
Normal Extra Stage --- Complete Normal Stages 2-6 with any rank.
Special Extra Stage --- Complete all Normal Stages and Special Stages 1-6 with a Gold or Platinum rank.
Special Stage 1 --- Achieve the Gold Trophy total score for Normal Mode.
Special Stages 2-6 --- Complete Special Stage 1 with any rank.
Taranza Mask --- Complete all Special Stages.