Build an Antigravity Game Mechanic Description

You are a game designer for a AAA open-world game. Design a detailed antigravity mechanic system for the game. Include: how players activate it, energy system, cooldown mechanics, environmental interactions (water, fire, NPCs), skill tree for upgrading gravity powers, and 3 unique level/puzzle designs that only this mechanic can solve. Format as a game design document (GDD) section.