|“||Kirby! Follow me! We can fight Necrodeus together!”|
|— to Kirby • Kirby Mass Attack|
The heroic heart is a star-shaped object which glitters permanently with blue-white light. How bright it glitters depends on how urgent the action is - for example, if the player taps repeatedly on the screen, the heart will glow brightly and the Kirbys dash instead of walking towards it.
As the heroic heart's name suggests, it is Kirby's own heart. The heart is seen communicating its thoughts with the remaining Kirby after his first encounter with Necrodeus - it is likely that Kirby has to make conscious effort to follow its direction simply because he has been separated from it. Should all the Kirbys be KO'd in a stage, the heroic heart disappears, and the game ends with a lone gray-angel Kirby floating in the air.
Kirby Mass Attack is the first time where Kirby loses his heart after being split into multiple Kirbys, although such separation has happened previously in Kirby & The Amazing Mirror and in the Kirby: Right Back at Ya! episode The Fofa Factor.
Gameplay wise, the heroic heart serves as the player's cursor to direct the Kirbys with. In effect, it shares largely the same roles as the Magical Paintbrush does in Kirby: Canvas Curse, although the heroic heart can be seen on the screen during gameplay, unlike the Paintbrush. However, the heroic heart disappears after a few moments if the stylus is not touching the screen of the Nintendo DS.
- The heroic heart is expressed as a common noun, unlike most of the other unique characters or features in the game, including the Magical Paintbrush.
- It is most likely referred to as Kirby's "heart" as a reference to the cliché to "follow one's heart:" Kirby literally follows his heart throughout the game.
- The European Kirby Mass Attack website simply calls the heroic heart a "golden star," and describes the game's controls as if Kirby follows a number of them.
- The official Japanese and European Kirby Mass Attack websites allow the user to control the heroic heart by clicking on the screen and dragging with the mouse. Ten Kirbys will follow it, but they cannot grab hold of the heart nor be flicked like in the game.
- In the Music Room in Kirby and the Rainbow Curse, Kirby Mass Attack is represented by an image of eight Kirbys clinging to the heroic heart.