You'll lead some gigantic armies into battle, but selecting units is surprisingly easy.ДЄfter the Terrans, there's a genuine bodyshock to it, actually: you're out of the toybox and into the flower bed where nasty things burrow and squirm. With ex-Ghost Sarah Kerrigan at the helm, you're still told your forces are under threat, but it can be hard to believe that when you see the Zerg on the battlefield, erupting from their eggs and racing across the landscape in a thick-pile rush of dripping mandibles. Wings of Liberty's campaign took pains to cast you as the scrappy underdog: a cadre of deep-space smokey joes, ekeing out a good time around the Wurlitzer while they rocketed from one guerrilla battle to the next. The Zerg are a great fit for Blizzard, and Heart of the Swarm sees them playing to the developer's strengths in excess. It's a study in escalation that challenges Katamari Damacy, but it's also a dazzling clash of textures and shapes as the hard edges of the Protoss are overwhelmed by the wriggling mass at your command. Minutes later you're a towering brood mother directing quivering hordes of Zerglings to ravage whatever remains of the crew. You start off as a single larva, avoiding patrols as you gather the essence you need in order to evolve.

A mission situated towards the end of the 20-level campaign, it's set on a Protoss ship and blessed with a simple objective: infest.

It might as well be labelled: Oh, go on then.Д®nemy Within is a case in point. An unknown unit turns up, an old ally learns a fresh trick, a new button suddenly appears on the UI. This is a sensation you'll revel in at carefully spaced moments slung throughout Heart of the Swarm's single-player campaign.

It's the fact that this developer, above almost all others, knows when to give you so much power that you start to feel bad for the people you're up against. The hallmark of a Blizzard game isn't the art, the schoolyard pulpiness of the subject matter or even the depths of tinkering each project endures before it's finally presented to the public.

As our single score attests, however, there's a unifying principle at work: an attempt to broaden the reach of strategy gaming without sacrificing its deeper pleasures. Part galactic soap opera and part chess match, part game and part sport, StarCraft 2 sounds like a potentially unwieldy beast. Then our multiplayer man Rich Stanton looks at the refinement and rebalancing of a genuine gaming phenomenon. First, Christian Donlan turns his attention to Heart of the Swarm's campaign, which shifts the storyline's focus from the Terran forces to a wronged Sarah Kerrigan, the former Queen of Blades, as she starts to rebuild the various wriggling broods of the Zerg. That's why we've chosen to examine each element separately - and with separate reviewers. Like Wings of Liberty, the foundation it builds upon, it's a real-time strategy game that has dared to pull its single-player and multiplayer components apart, balancing units differently for each mode and locking out dazzling solo toys when they'd unbalance competitive games. StarCraft 2: Heart of the Swarm may be classed as an expansion, but it's also a couple of games in one.

Heart of swarm new units