From WiKirby, your independent source of Kirby knowledge.
Party Ball is an item which appears in the Top Ride mode of Kirby Air Ride. It appears randomly during standard races, dropping onto the course. When touched by a racer, the item is activated, causing a large Party Ball to appear over the race track. After a few seconds, it opens, showering about a dozen random items onto the course, which scatter in random directions before touching the ground. The only items that cannot be dropped by a Party Ball are other Party Balls and items that have been disabled or not unlocked yet.
Once picked up, the Party Ball is used right away, with no further input needed from the racer.
Party Ball opens to reveal lots of different items.
Names in other languages
"Kusudama" is a type of Japanese decoration made from origami. Translated as such in Super Smash Bros.