Star Wars: The Force Unleashed II

Force Fury is the temporary power boost that truly magnifies your powers and makes you, in most cases, invincible. As you kill enemies, in the down-left corner of your HUD, you’ll see a symbol later on with a weird shape with a blue “filling.” Once it reaches the maximum, it’ll shine in a way. Use and together to activate Force Fury. You will probably unlock this trophy in the Unleashed playthrough but if not, simply choose a level, attack until it fills up. Then reach a checkpoint (the saving symbol will appear in the bottom right corner of the screen). Once that happens, activate, then save, then exit. From the main menu choose “Continue.” You will be at that checkpoint again. Activate, save, quit, continue, rinse and repeat until the trophy unlocks.

However, the easiest and quickest place to unlock this trophy is in the first level, "Kamino: the Escape," as per the tip provided by SaberBlade:

If you replay Kamino (or if you're on your first playthrough), once you have to activate Force Fury, turn it on, then turn it off again, then on again and off again. Keep turning it on and then off again until the trophy unlocks. This is the only time in the game where you'll have infinite fury and the ability to turn it on and off constantly.