The Supercharged Gravity Gun — Half-Life 2 Walkthrough

Upon entering the Citadel, you'll be caught in an energy field that supercharges your Gravity Gun. It now glows blue and can pick up and launch living enemies, as well as deal immense damage to Combine technology. This transforms the Gravity Gun into your primary weapon for the remainder of the game. Use it to rip apart Combine Soldiers, destroy turrets, and even dismantle Striders. Experiment with its new power; it's incredibly satisfying. You'll need to navigate through the Citadel's complex interior, which is filled with Combine technology and traps.