|“||If you clear certain stages, a rainbow bubble appears. When you get a rainbow bubble, a rainbow bridge is built, and you can proceed to the next area on the stage-selection screen.”|
|— Instruction manual description • Kirby Mass Attack|
A rainbow bubble, as its name implies, is a bubble containing rainbow colors.
Rainbow bubbles appear at the end of certain stages. Flicking one or more Kirbys at a rainbow bubble causes them to pull it down to the ground. The bubble pops and its rainbow core rises into the air. The core sheds its seven colors and vanishes, and the colors create a rainbow bridge. The Kirbys then immediately run across it.
Three rainbow bubbles exist on each of the Popopo Islands (with the exception of Necro Nebula, which is completely devoid of them). When a rainbow bridge is created, the cloud covering the stage-selection screen shrinks, thus, stages are unlocked. Once the Kirbys have created the third rainbow bridge on a given island, that island's boss can be challenged.
|“||Watch for these bubbles. Pop them to move onward.”|
|— In-game description • Kirby Mass Attack|
|“||Sometimes you'll need to build a rainbow bridge to continue onward. To do that, you'll need to find the rainbow bubble that holds such a bridge.”|
|— Daroach • Kirby Mass Attack|