Sergeant James Heller is faster than a speeding bullet, more powerful than a locomotive, and able to leap tall buildings in a single bound. But that’s where his similarities with a certain man of steel end. Because Heller, contrary to Kal-El and his mild-mannered alter ego, has absolutely no problem with laying waste to a city block if it gets him what he wants. And what he wants is revenge. In Prototype 2, Heller has a bone to pick with Alex Mercer, the star of 2009’s decent, if uninspiring, Prototype – and he’s not fussy about collateral damage along the way.

Prototype 2, developed by Canadian outfit Radical Entertainment, is a third-person, free-roaming sandbox game set in a New York City ravaged by the Blacklight virus that was featured in the original. Heller, a no-nonsense army soldier, returns home to find his family dead, and Mercer in his crosshairs. I won’t spoil the opening storyline, but Heller ends up with superhuman powers of his own, and tears apart the infected parts of NYC in a bid to make somebody pay for what’s happened to him. What makes Heller so very interesting is his total and absolute lack of a moral compass. He’s so blinded by rage, so intent on exacting revenge, that he lacks even the slightest hesitation when it comes to punishing the men and women of the organizations he sees as complicit in his suffering. And if a crowd of innocents get between him and Mercer, well… that’s too bad.

Heller’s powers are a fascinating mix of the very cool, and the very, very disturbing. He can leap over city blocks and reflect rockets, but he can also regenerate his health by ripping people’s heads off and consuming them wholesale. He can assume their appearance (very cool), or stick his fingers inside them to turn them into virus-riddled human bombs (very disturbing). There’s a more tactical bent to the gameplay this time around, and posing as a member of the military or a scientist is a fundamental part of completing many missions. During the initial portion of the game, you feel slightly overpowered as you take out entire platoons with a single attack. But Prototype 2 cleverly ramps up the scale of conflict to match the evolution of your abilities. Heller’s initial load-out seems to make him invulnerable, but as the forces against you steadily increase, you’ll realize that you need each and every one of your overblown abilities to just survive, let alone excel.

The toys are truly excellent, but it’s the storyline and the characterization that make this a great game, rather than just a good one. We’ve seen excellent mechanics in titles before, and we’ve seen lush environments. But it’s only been in truly excellent games – such as Arkham City or Mass Effect – where the appeal is born of a careful balance between what you can do, and why you would be interested in doing it. Radical have taken a brave step in creating a protagonist with little in the way of redeeming features. Heller’s laidback attitude to civilian casualties, friendly fire or wanton destruction make him the archetypal antihero, but somehow, the game manages to keep you rooting for him (even when, during one memorable mission, he threatens to literally eat his target’s face). Heller is a man on the edge, a few wrong moves away from becoming the very thing he claims to be hunting. And it’s a somewhat bewildering experience to wonder at your own character’s mental stability – as you fling Heller from one conflagration to the next, you can’t really be sure what he’s going to do once he gets there. Clinging onto that ragged edge is a fascinating, and unnerving, gameplay experience.

Prototype 2 has excellent free-roaming, incredibly satisfying combat mechanics – you haven’t lived until you’ve destroyed a helicopter by throwing a tank at it – and a story that doesn’t feel shoe-horned in just to accommodate a sequel. It would have been very easy for Radical to polish up Prototype and simply send Mercer out for another spin. Turning the nature and tone of the game on its head is exceedingly brave, and taking a risk on a lead character that doesn’t even live in the moral grey area (Heller is, let’s face it, a nasty piece of work) borders on lunacy. But the result is inspired.