Event 28: Puffballs Unite!
From SmashWiki, the Super Smash Bros. wiki
The player can choose a character to defeat 14 Kirbys from the Kirby Team (4 at a time) on the Green Greens stage. This event match is similar to the match in Adventure Mode, where each of the Kirbys is wearing a Kirby Hat, giving every Kirby a unique neutral special move. However, despite its similarity to Stage 5 of Adventure where the player fights the Kirby Team, the player has one stock as opposed up to five. The Kirbys in this event are heavier than in Adventure Mode. This event has a rather strict time limit of 2 minutes, where the event will end in failure if the player fails to KO every Kirby within that time limit.