Bumper Bubbles

Bumper Bubbles (also known as Rain of Thorns in North America) a Free-for-All minigame featured in Mario Party 9. Its name is a pun on bumper cars.

Introduction
The players swim in their bubbles up to the center from offscreen. They then fall back to the bottom of the screen.

Gameplay
Players try to collect and keep as many balloons as they can, while avoiding Spiked Balls. If a player collides with a Spiked Ball, all of their balloons are released and they fall off the screen temporarily. Players can bump other players by colliding with them. Five balloons spawn every four seconds until the last five seconds of the game. After 60 seconds, the players with the most balloons wins.