It's funny to imagine Blizzard's eight core values as bullet points on the back of a self-help book for video gamers: Gameplay First; Learn & Grow; Commit To Quality; Think Globally; Embrace Your Inner Geek; Lead Responsibly; Every Voice Matters and Play Nice; Play Fair. In outlining the eight tenets its staff must always adhere to, Blizzard's head honchos have carved into virtual stone gaming's version of the Ten Commandments. If we follow them religiously as we twat wild boars with sticks in World of Warcraft, will we go to virtual heaven when we die?

One of the eight core values, however, seems particularly apt when it comes to StarCraft II. "Embrace Your Inner Geek" Blizzard co-founder and StarCraft II executive producer Frank Pearce's Powerpoint slide says. Here we have the sequel to a 12-year-old game that South Koreans and a handful of Westerners can make a living out of playing professionally. Here we have a real-time strategy game, perhaps the most hardcore of all game genres. And here we have science fiction in all its cliché-ridden glory: beefcake marines, mysterious space elves and terrifying insect-like aliens.

So when Frank takes me through his presentation of what will undoubtedly be one of the biggest games of 2010, I embrace my inner geek with all the might of an imaginary bear hug, as so many of you have already done while playing StarCraft II's multiplayer-only beta.

If the beta has taught us anything, it is that, when it comes to multiplayer, StarCraft II is a lot like StarCraft: three races - terran, protoss and zerg - base building, resource gathering, big armies, a top down perspective, a vibrant, colourful art style and a markedly familiar feel. The game might have new units, like the jet pack carrying Terran Reaper, but fans who were there back in the day (when it comes to StarCraft, back in the day actually means something) will be able to pick the sequel up and party like it's 1998.

But what of the single-player? At a time when Relic Entertainment is re-writing the real-time strategy rulebook with its role-playing-esque Dawn of War series, and modern tastes demand more accessible, plot-driven experiences, what is it about StarCraft II's single-player that moves the series forward? That's what I'm in a plush West End hotel with Frank to find out.

On the reverse of Blizzard's glossy A4 promotional sheet for the game, there's a picture of Tychus and a quote:

Wings of Liberty, the first of three planned StarCraft II games, is set four years after the events of StarCraft expansion Brood War. Sci-fi cowboy Jim Raynor is leading a rebellion against Dominion emperor Mengsk aboard his battle cruiser The Hyperion. StarCraft II's story is told through hammy cutscenes, with voice-acting lifted straight out of the Serenity stable of science fiction, but they're all beautifully rendered in real-time by the game's impressive graphics engine. "The technology for the engine is really quite cool," Pearce enthuses. "It's come a long way since the original StarCraft." Of particular note are character faces, which all look superb. In one early cutscene we see Raynor drinking in a bar, disconsolate. In walks his old chum Tychus Findlay, a cigar-chomping ex-convict who stomps about in the biggest blue suit of space marine armour you ever did see. Tychus has a business proposition: he knows a bloke who'll pay top dollar for alien artefacts liberated from the Dominion. The two trade gravely-voiced insults before coming to an arrangement.

In a later cutscene the horrible zerg turn up, attacking the Hyperion as it makes its getaway with the aforementioned artefact. The Queen of Blades, the zerg who used to be the human Kerrigan and Raynor's former squeeze, is leading the attack. Raynor blames himself for Kerrigan's unfortunate capture, and has turned to drink. "I always knew she'd be back," Raynor says. "What's she after?"

The Hyperion's Cantina - where sorrows are drowned and mercs are hired.

I go hands on after Raynor and his Raiders have "liberated" the alien artefact. He is standing in the Bridge, studying StarCraft II's star map. Clicking on it, I have four different missions available to play at this point during the campaign, all part of the game's "branching storyline". Next to Raynor stands faithful first officer Matt Horner. The perspective is fixed in place. When I click on Raynor he says something depressing about the zerg. When I click on Horner, the two share a cutscene where they chat about their new cargo: the mysterious alien artefact. Tosh, an untrustworthy voodoo-loving operative who's part of a secret project called the Spectres (next-gen Ghosts), stands in the background. Talking to him, he suggests "another job". But what's in it for Jim? "Everyone knows Jim Raynor wants to put the hurt on Mengsk," Tosh says. "I can help you with that. I can help you big time." Once the cutscene is over, it's back to the fixed bridge view.

From here I can visit the Hyperion's three other sections with a simple click of the left mouse button. In the Armoury stands Swann, a rotund, short fellow who would almost certainly be a dwarf were he in Warcraft. Here cash I've earned through completing missions can be spent on upgrading my infantry, vehicles and structures (with the aid of nifty little videos that demonstrate the text descriptions. I was able to buy almost all the upgrades in one fell swoop, but then my coffers were packed with unspent cash gained from the game's first few of missions; in reality careful, considered spending will be essential.

In the Laboratory the hyperactive geek Stetmann (look closely and you'll see small squares of tissue paper covering up shaving cuts on his face) messes about with experimental research and the sexy female scientist Hanson ponders the alien artefact. Talking to Stetmann for the first time, he explains the research opportunities system. During missions you can earn research points from optional secondary objectives, the idea being that it takes more skill to search out side areas of the map that might have hidden protoss technology items or zerg artefacts while you're tackling primary objectives. Research points are spent in two research ladders: one for protoss and one for zerg. Every five levels you get to choose one research upgrade from a choice of two. The first choice you'll make on the protoss ladder is between adding Ultra-Capacitors or Vanadium Plating. The Capacitors will make weapon upgrades increase your units' attack speed by five per cent in addition to increasing damage. The Plating, on the other hand, will make armour upgrades increase health by five per cent in addition to increasing armour; basically, do you want to kick more ass or take more punishment? Further up the ladder, at the 20 points of research mark, I can snag the Science Vessel - a classic unit from the original StarCraft which doesn't appear in the SCII multiplayer because it would unbalance the gameplay - or take the Raven, which does appear in the terran multiplayer army.

The idea with the Lab research panel, and the Armoury research panel to an extent, is that you'll get your grubby mitts on unique, super powerful units that aren't in the multiplayer. Take, for example, the giant transport that can carry dozens of infantry units and soak up loads of anti-air abuse. The transport, obviously, isn't balanced for multiplayer, but it is loads of fun to mess around with in single-player. Blizzard also hopes the A or B system will add replayability - maybe you'll play the campaign again just to try out the units you passed up on previously.

The Cantina's easily the best section of the ship, though. It's packed with lovely little details: a The Lost Vikings arcade cabinet (Google that Blizzard fans) which will hopefully be playable in the final build, a television that sprouts satirical news reports, and Elvis Presley's Suspicious Minds busting out of the jukebox. Here I can hire powerful mercenary units from a broker called Hill. Mercs are great: Devil Dogs are, basically, elite Firebats. Hire Hammer Securities and you'll get Elite Marauders - one of the best infantry units in the game. Out on the battlefield, hired mercenaries instantly spawn from your mercenary building, once you've got enough minerals and gas.

Click on the Cantina's television and you get a news report

Navigating the Hyperion brings back hazy memories of Wing Commander and a live action Mark Hamill hamming it up in front of a green screen. It's an old school system but there's something refreshing and exciting about it. Just being able to click on people and trigger a cutscene (the game's packed with non-interactive in-game engine cutscenes, almost 45 minutes worth according to Blizzard) isn't something we're used to from RTS games. Sure, StarCraft II's story isn't going to win any writing awards, but there's a cool Event Horizon vibe going on. Talk to Hanson and Raynor will ask whether the alien artefact could be behind some strange noises and other creepy shenanigans the crew's reporting. She dismisses the concern, but it's obvious the artefact will end up playing a major role in Raynor's battle against the Dominion. As you'd expect, Frank is enthusiastic about StarCraft II's single-player, highlighting the game's 29 missions, branching campaign and lovely cutscenes: "This is by far our most ambitious story mode campaign for an RTS ever."

Still, you, the player, will spend more time pointing and clicking and commanding and conquering than marvelling at lip-synching. The terran campaign will live or die by the quality of its missions. Thankfully, the two available for play test suggest StarCraft II will most certainly live.

Welcome to the Jungle (Blizzard hasn't licensed any Guns N' Roses songs, but you won't care - the music is superb) tasks you with escorting SCVs as they harvest seven canisters of Terrazine gas on a map defended by the fanatic Tal'darim protoss clan. The mission quickly spirals out of control - you have to recover the Terrazine while dealing with protoss base rushes (anti-air Goliath units do a great job here), and their attempt to seal the Terrazine away. Once seven bits of Terrazine have been brought back to your base, the mission ends. In a nice twist, the Terrazine becomes a bone of contention back on the Hyperion Bridge. It turns out that Tosh, who initiated the mission, wasn't exactly upfront about his motivations.

Some of the research upgrades will make your job on the battlefield much easier

The second mission, called The Dig, is the highlight of our play test. Tychus asks you to recover an alien artefact from a planet called Xil. It's a morgue, he says, packed with ruins excavated by the missing "Moebius" team. The mission begins with a drop off - you're in control of seven units: four marines, a Marauder and two medics. It's not long, though, before you encounter Tal'darim protoss. Swann drops off Siege Tanks, which you use in siege mode to rain down artillery from a safe distance. Soon after you find the Moebius team, start building a base and fire up a giant laser to melt down an ancient temple door.

The mission then expands to multiple fronts. As the laser ekes down the temple door's many, many hit points, protoss attack from all directions. Merc units packed into bunkers placed in choke points leading in and out of my base, coupled with as many siege tanks as my economy provides, make short work of the AI. Then, I get to control the laser myself. F2 selects it and the right mouse button fires, disintegrating pretty much any enemy unit from halfway across the map. The relentless assault continues until I eventually bust down the temple door. Wicked.

It's these kinds of interesting mechanics that should propel StarCraft II's campaign missions above the glorified multiplayer tutorial fare we're used to from most RTS games. And, by the sound of it, the rest of the missions will be just as good. In one players will have to contend with an active volcano that spews lava flow onto low ground - coincidentally exactly where the resources you need are. In another, a star is exploding, launching a wall of fire that marches across the map. You have to get your resources and complete your objectives while fleeing the burning doom bringer.

Almost as impressive as the cutscenes is the new and improved, which Blizzard is billing as the Xbox LIVE of online PC gaming. Some of its social features, in addition to the in-depth profile statistics and in-game achievements, are truly impressive. You can add friends via Facebook integration, or add them with email addresses via the new Real ID system - entirely optional, Pearce says with reference to the paranoid.

The best thing about Real ID is that it'll give you access to cross-game chat. Say, for example, you're playing StarCraft II's single-player campaign and your guild mates are playing World of Warcraft. They'll be able to quickly and easily ask you to fill a space in a raid, and you'll be able to quickly and easily answer the call. Or, say you're playing StarCraft II, but really you're waiting for a heroic dungeon run in WoW. You can leave a message saying just that as a status broadcast. Then when your mates jump into WoW, they'll see the message and be able to pull you in. Cross-game chat will work for all Blizzard games: StarCraft, Warcraft, Diablo, or, if the developer has something brand new up its sleeve, that as well. Basically, it'll bring together players of all Blizzard's games into one happy blob of gaming goodness, plugged in to the company's all-encompassing, all conquering Matrix digital hive mind.

The cutscenes are great - it's obvious Blizzard's put loads of work into the terran campaign.

So, finally, StarCraft II's gloves have come off. We knew the multiplayer side of things will provide a wonderfully-balanced but familiar experience. Now we know the single-player will be much more than the poor cousin. For those of us who love RTS games but dare not battle other players online, this is hugely exciting. With StarCraft II's release only a couple of months away, it won't be long before we're all embracing our inner geek.

StarCraft II is due out on the PC on July 27.