Entropy: Zero 2 lets Half-Life 2 players experience the Combine side of the fight

Most of us have spent our time in Half-Life 2 fighting the Combine, blowing up their equipment, and generally making Gordon Freeman the biggest headache the occupation has ever encountered.

Entropy: Zero 2 offers a rather different perspective. This time, you're working for the other side.

Created by Breadmen, this free, fully voiced campaign puts players in the boots of Bad Cop, a Combine soldier tasked with hunting down Judith Mossman. Across seven chapters, you'll fight through new environments, command squads of Combine troops, encounter redesigned enemies, and make use of weapons and equipment that change the familiar Half-Life combat experience. The journey takes you through places including Nova Prospekt and the Arbeit Communications facility, with an arctic vehicle section thrown in for good measure.

And then there are the Xen grenades, which can swallow enemies and objects before spawning creatures from Xen in their place. Because apparently conventional explosives weren't causing enough problems already.

But the real attraction here is the change in perspective. Half-Life has always been so closely associated with Gordon Freeman and the resistance that stepping into the role of a Combine soldier opens up an entirely different side of that world. The project has its own characters, dialogue, story, and combat systems, giving it far more personality than a simple collection of new maps.

Entropy: Zero 2 is a single-player experience requiring Half-Life 2, and the developers include a photosensitivity warning for flashing effects.

For longtime Half-Life fans, it's one of those projects that makes you appreciate just how much room there still is for new stories inside Valve's universe. Even when you're playing as one of the people you'd normally be trying to shoot.