Rocketbarrel Boost is Diddy Kong's personal and special move, allowing him to fly temporarily by using a rocketbarrel pack on his back.
Donkey Kong 64
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.
Donkey Kong Country Returns and Donkey Kong Country Returns 3D
In Donkey Kong Country Returns and Donkey Kong Country Returns 3D, Diddy Kong will always activate the rocket pack if the player hold the jump button when the primate is dropping down, delaying his fall. However, the fuel in the rocket pack is limited, enabling flight only for a couple of seconds. In the single player mode, when Diddy is mounted on Donkey Kong's back, the rocket pack carries both Kongs, allowing them to correct jumps, cross gaps and avoid hazards. Diddy can also carry Rambi the Rhinoceros, but the extra weight decreases the duration of the flight even more. In the multiplayer mode, Diddy Kong can fly alone for a bit longer thanks to his low weight.
Donkey Kong Country: Tropical Freeze
The rocket pack is also present in Donkey Kong Country: Tropical Freeze, being used by Diddy Kong in similar way to the one in Donkey Kong Country Returns and Donkey Kong Country Returns 3D.
Super Smash Bros. series
The Rocketbarrel Boost is Diddy Kong's Up Special Move in the Super Smash Bros. series. It is his basic "recovery" move. Diddy can also charge the rocketbarrel boost, and when fully charged, it goes a longer distance, and it can be angled left or right as well. The distance depends on how long the move was charged.