Futari wa Precure Max Heart: Danzen! DS de Precure Chikara o Awasete Dai Battle Cheats - Nintendo DS

Extra Unlockable Art and Cutscenes
Though you'll obtain much of the game's art gallery in a single playthrough, you'll still be missing a few scenes and art. You'll have to play through the game again with the third bonus character in order to get them all.

Extra end of game screen - Beat the game with Shiny Luminous as the primary character
Shiny Luminous and Cure Black art - Have Shiny Luminous and Cure Black team up, then revive Cure Black when she gets knocked out
Shiny Luminous and Cure White art - Have Shiny Luminous and Cure White team up, then revive Cure White when she gets knocked out
Shiny Luminous transformation scene - Choose Hikari Kujou/Shiny Luminous as the primary character

Various Unlockables
When you first start the game, you'll only be able to select the Arcade Mode. Beating it, however, unlocks a few extra features and modes. You'll be able to unlock a third playable character, a gallery with various cutscenes and art, level select, and a few mini-games.

Gallery - Beat Arcade Mode
Hikari Kujou/Shiny Luminous - Beat Arcade Mode
Level Select - Beat Arcade Mode
Mini-Game Mode - Beat Arcade Mode