Rocket Rumble is one of the ten game modes in Kirby Battle Royale. Players collect fuel for their rockets for a minute, while being able to attack rivals and their rockets. The player/team with the greatest altitude wins. It is unlocked for 800 battle coins.
Rocket Rumble is first played in the third Bronze League Battle during the Story Mode.
Players collect Fuel, which mostly appear as green blocks, that are shot from cannons that resemble Moto Shotzos. Like in Apple Scramble, players can pick up Fuel, and other players, in a stack by pressing R, and press B to throw them. Fuel can then be thrown into a rocket, preferably the player's own rocket, with a numbered rocket present in each of the corners of the arena, one assigned to each player. Players can attack rivals to slow them down, cause them to drop their fuel, or put them in a prone state for a short amount of time. Players can also attack rival rockets and cause them to drop fuel that can be stolen. Time Bombs also appear, and can cause massive damage to rivals and rockets alike. After some time has passed, large gold-colored blocks of Mega Fuel, which are worth five Fuel each, will start to appear in the arena. During the last ten seconds of the match, the rockets open up, and a count-down will play. Players can use these last ten seconds to gather any remaining fuel or enter their rockets; a player must be in a rocket during take off in order to earn points.
During a team battle, there are two rockets for each team, and during take-off, they will merge to form a large rocket for each team; however, if one of the teammates does not enter their rocket, that team will only use the fuel from the rocket that did launch.
Space Center is the only stage in Rocket Rumble. It features a rocket in each corner, labeled with a number corresponding to the player: Player 1 is in the top left, Player 2 is in the bottom left, Player 3 is in the top right, and Player 4 is in the bottom right. Moto Shotzos are positioned at the sides of the stage, dispensing Fuel and eventually Mega Fuel. Time Bombs appear eventually, spawning in the center of the stage. The last Time Bomb to appear will always be timed to explode on the last second of the match, potentially knocking fuel out of a rocket while its occupant is powerless to stop it. When playing a team battle, teams are in the left and right sides of the stage. Players of a team can enter either rocket of their color.