Jetpack
The Jetpack activates when the player holds Jump while in the air, providing an explicitly described airborne control input.
How it works
The source states that holding Jump while in the air activates the Jetpack. To unlock it, the passage directs the player to return Randy's Nose to Randy Marshmallow in the Cinema area, identified as the Red Area on the map, in Haven City. It does not specify duration, fuel, lift, or other performance details.
Read the supporting references
A factual reference to eleven named gadgets and their reported effects, activation conditions, and unlock clues from the retrieved Gadgets passage. It does not compare effectiveness or verify behavior beyond that passage. Guidance explains the referenced mechanics; it is not a tested damage ranking. Check the stated edition and source version before applying a patch-specific detail.