The rocket pack first appeared in Donkey Kong 64. After reaching the level Angry Aztec and purchasing the potion Rocketbarrel Boost (Boostum Highus) from Cranky Kong's Lab for five red Banana Coins, Diddy Kong will be able to activate the move by jumping into his barrels. By expending Crystal Coconuts and avoiding touch the ground, the little Kong will be capable of flying upward, and back and forward. During the flight, Diddy's Peanut Popguns will be always drawn, allowing him to shoot straight forward, even though he can only fire four peanuts at a time. The Rocketbarrel ability is notorious for being clunky and very hard to control, especially when competing in the ring courses. If he attempts to go anywhere beyond the permitted boundaries of this power-up, a red no symbol will appear and his rocketbarrel will vanish and send him free-falling – which in many cases if he attempts to go to Crocodile Isle and sneak into the lobby of Hideout Helm that may only be accessed later in the game via Tiny Kong's Monkeyport.