A ship appears at the scene shooting cannonballs at an island that bobs and tilts. The players have to avoid falling down into the ocean while the cannonballs hit the island.
If one of the cannonballs hits the island and one of the players has failed to jump to avoid the shockwave, the player is temporary stunned. If the player is caught right under the bomb, they will be blasted off the island and into the water, where a Blooper picks up the character.
In Mario Party 2, when the clock reaches 5 seconds, the ship will engage a very powerful missile that has a wider blast radius than the standard Bullet Bills fired onto the island. The game ends when there is either one player remaining, or the time runs out (in which case all remaining players win). Also, this Mini-Game starts with a whistle blow instead of the harmonica from the previous game.
In both games, a draw takes place if the remaining players get eliminated.
In the Mini-Game Island and Mini-Game Coaster, the player must stay on the platform for the whole 30 seconds to clear. Even if the 3 CPU players are eliminated, if the player doesn't last 30 seconds, the player misses.
- - Move
- - Jump
- Game Rules – "Cannons are aimed at the floating island. The island bobs and tilts with the waves, so don't fall in!"
- Game Rules (Mini-Game Island) – "Try not to fall off the bobbing, floating island. Stay on the island until time runs out to clear the game."
- Advice – "If a cannon ball hits the island, your head spins and you can't move. So jump the moment it hits to dodge it."
Mario Party 2
- Game Rules – "The floating island is under fire again, this time from Bowser's bombs! Hang on tight to win the prize!"
- Game Rules (Mini-Game Coaster) – "The floating isle is under attack by Bowser's ship! Stay on the island until time runs out to clear."
- Advice – "Just as time is running out, you'll find Bowser's ship has saved its best shot for last. Watch out!"