Blizzard Entertainment has provided plenty of details about the upcoming StarCraft sequel but it can be hard to gather all the nuggets together from the various previews and interviews and hands on sessions. To give you one single place to go to read all the information about the game, we've put together this comprehensive overview of most of what we know about StarCraft 2.

That includes full details on everything we know about the story and a complete rundown on the nature and abilities of each and every unit we've seen. We'll close things out with a look at some of the maps we know are going to be part of the game.

It's important to keep in mind, though, that the game is, as of the time of writing, still undergoing balance and unit tests, and is liable to change. Like, a lot.

Even so, there's a lot to talk about with this game, so let's get right to it.

Blizzard caused a great deal of controversy when they announced that StarCraft 2 would be released as three separate chapters, or episodes. Some saw this move as shameless money grabbing, but Blizzard defended the move, saying it was intended to make each individual chapter to be a full, engrossing single-player experience.

The first of these episodes, Wings of Liberty, is allegedly due out sometime during 2010 and will focus on the Terran storyline and Jim Raynor. Wings of Liberty is taking a page from Dawn of War's book and offering some non-linearity to the storyline. Once players make it into the gooey-caramel-center-part of the game, they are given a selection of missions to choose from. Which missions you choose and what kinds of choices you make will ultimately have an effect on how Jim's character develops, which makes it sound like there'll probably be multiple endings and unlockables.

Story-wise, Jim and his troops are blue and broke. In an attempt to fix both problems at once, Raynor and his Raiders take up different missions across the galaxy to earn cash, while at the same time collecting new troops for his growing army. Along the way, he'll also hunt for alien artifacts, which can be researched for stat bonuses for his forces. Outside of these details... well, we don't want to spoil it. Mostly because we don't know what happens either.

At some point after Wings of Liberty (which is to say, when it is ready), Blizzard will release the second episode, Heart of the Swarm, which will follow the events of the Zerg and the Zergified Sarah Kerrigan. And after that (possibly around the year 2067) the Protoss episode, Legacy of the Void, will continue the saga centered on Zeratul, a Protoss Dark Templar.

The MULE is a new harvesting unit. Whereas the SCVs can harvest as well as repair and build, the MULEs can just harvest. They can hold three times more minerals than SCVs, but have a limited lifespan and will, left to their own devices, eventually expire.

The Hellion, a four-wheeled flame-throwing buggy, replaces that crummy old missile-launching Vulture Hoverbike. Despite the bizarre technological backstep, Hellions provide an important link in terms of balance. In the original StarCraft, Firebats (rather slow-moving flame-throwing infantry) were used for tearing down infantry swarms and constructs, but moving slower than other infantry made them pretty useless in most combat situations. The speedy Hellions now fix that little problem.

Medivacs are card-carrying members of the consolidation club, too, replacing both the medic (from Brood War) and the dropship (from vanilla StarCraft). Capable of ferrying ground units across the map, and of healing infantry units, the Medivac is likely to become a central unit for most strategies.

Reapers are awesome. Reapers are so awesome. If the movie The Rocketeer starred Bruce Willis in his Die Hard 3 era, and was directed by John Woo, you'd get something about half as badass as a Reaper. That said, you could just look at Dawn of War's Tactical Marines and get something pretty much identical. Reapers are dual-pistol-wielding jetpack-wearing light infantry. They're fast, relatively cheap, and best of all, can traverse cliffs, making them one of the most mobile and flexible units in the game. And they look awesome.

Though maybe not as awesome as a Thor. Essentially the battle cruiser of ground units, Thors are hulking, armored, killing machines. With four anti-air guns mounted on its back, and two particle-accelerator cannons for dealing with punks on the land, Thors have no discernable weakness, beyond the huge amount of time and resources required to climb the tech-tree high enough to produce them, and then the (slightly less) huge amount of resources required to actually make one.

Marauders are like less-awesome Reapers. Sure, they're bigger, and sure, they can fire concussion missiles that slow ground units down, and sure, they tear armored units to shreds, but can they fly up cliffs? No? Pfft, whatever.

The Banshee is a thing to be feared. A very powerful air-to-ground unit, the banshee is capable of blowing through almost anything with legs or wheels. Oh, and it can cloak. Its only truly reliable counter are flying anti-air units like the Corruptor or the Phoenix.

The Raven is similar to the science vessel from the original and is incapable of any standard attack. Instead, it's a detector, so burrowed or cloaked units can't hide. It can lay down auto-turrets (with no set lifespan) for a fairly small energy cost, and can drop "hunter-seeker missiles," floating bombs that track the movement of a single enemy, kill it on contact, and deal severe damage to any foes unlucky enough to be nearby. The only way to avoid the missile, in fact, is to run far, far away, making it a very impressive tactical weapon.

You may remember the Viking from a little-known 1980s cartoon called Transformers, when it was called Starscream. Yes, the Viking is a robot that can transform into a plane. Unlike Starscream, though, the Viking is much more effective as an aircraft than a crummy ground unit. It's a purpose-built anti-air aircraft; it just also happens to be a robot that can occasionally help on the ground, too.

Banelings are probably the most widely publicized new unit. These cute little critters are green and cuddly and explosive. Spawning Banelings requires you to morph your Zerglings, similar to the way you had to morph Mutalisks into guardians in the original. Banelings are functionally walking bombs, and a few well-placed Banelings can decimate an opposing army.

Queens were in the original StarCraft as extremely annoying flying units. In StarCraft 2, however, they are extremely useful ground units, capable of increasing the larvae output of your hives, as well as actually being able to attack.

Roaches are mid-sized ground units with a medium-ranged attack. They're not particularly impressive-looking, but are more than capable in combat. They regenerate their health at a very quick rate, and that rate doubles when a roach burrows underground. This makes them very potent for guerilla-style combat, as a heavily damaged Roach will be back to full health after only a few seconds out of the firing line.

The Infestor is a brand new stealth-unit that is not only capable of burrowing, but moving, and using abilities, while burrowed. Infestors don't have a standard attack, instead relying on a couple of extremely nasty tricks. Neural Parasite, the Infestor's default ability, allows you to take control of almost any enemy unit for ten seconds. Research will eventually let the Infestor spawn infested Terrans, and use a particularly potent ability called Fungal Growth as an area-of-effect delayed freeze. Any units (even your own) caught in the effect of Fungal Growth will be slowed down for six seconds, at which point they will be completely immobile for the next ten.

Corruptors are going to be a lot of fun. As a flying unit designed to only be able to attack other flying units, it's combat ability is somewhat limited, but check this: when you destroy a unit with a corruptor, it doesn't die – it becomes a corrupted version of itself that acts as an immobile turret. Corruptors are especially awesome when used against the Terran Banshees.

The Brood Lord looks suspiciously like the guardian from the original StarCraft, and that is because it is. It's a flying air-ground unit with siege range. However, the Brood Lord has a trump card that the silly old Guardian could never match: when it attacks, it launches a Mantaling (a small and weak ground creature) which can then join the fray. It's capable of turning a very small attacking army into a very large one.

Overseers are special detectors evolved from Overlords. They move faster than Overlords, and are capable of producing Changelings, which can shape-shift into Terran Marines for the purposes of spying. The longer an overseer remains in one place, the greater its radius of sight.

Spine Crawlers and Spore Crawlers aren't technically units, but they're the mobile equivalents of the spore and sunken colonies from the original. Being movable now means that you can expand without having to build more defensive buildings, and without compromising your original base layout. They can move while they're off the creep, but are substantially faster when they're on it. The crawlers replace the colonies.

Even when you look at them on paper, you can just tell that Stalkers were designed with the really competitive players in mind. Equivalent to the Dragoons from vanilla StarCraft, Stalkers are capable of attacking both land and air units with a mid-ranged attack. Although they are noticeably more fragile than Dragoons ever were, their default ability to instantly teleport a short distance more than makes up for their lack of defense. Players talented at micro-managing their units have used the blink ability to pull off some truly crazy feats.

The Warp Prism is probably the single most contentious unit so far. Capable of transporting any unit in the same way that the Terran Medivac can, the Warp Prism has a secondary function that blows the Medivac's healing out of the water. You see, the Warp Prism is capable of functioning as a mobile pylon. When combined with the brand new Protoss gateway structure, you can warp brand new units onto the field anywhere, even while keeping the warp prism out of line-of-sight.

The Colossus is definitely one of the coolest looking units out there, having an appearance somewhere between a War-of-the-Worlds-remake alien craft, and the striders from Half-Life 2. Counted as both a land and air unit in terms of what can attack it, the Colossus is rather fragile for its cost, especially when you factor in that it can only attack ground units. However, its attack can feasibly hit multiple units for fairly good damage, and its height and long legs allow it to traverse cliffs. Additionally, it can have its weapons upgraded to be capable of dealing damage from siege range, making it an excellent, and very mobile, base-raiding unit.

Zealots were the old Protoss basic unit, and now, well, they're still the Protoss basic unit, except with a neat little upgrade that makes them substantially more viable in the late game. Now they've got a researchable ability called Charge that increases their passive speed, and gives them the activated ability to quickly close the gap with any enemy in range, letting them get a-stabbin'.

The Disruptor is a personal favorite. Equipped with a nifty glowing beam weapon thing, the Disruptor's true function is in its innate and researched abilities. The first ability, coming with the Disruptor from the start, is the ability to create small, localized force fields on the fly. Units can't travel through the field, but ranged attacks can. There are videos out there of a couple well-placed force fields trapping half of an invading force outside a base, while the other half gets torn to shreds. The second ability, hallucination, creates false copies of allied units, making it tough for the enemy to choose which units to target (and theoretically giving you a fake numbers advantage).

The Phoenix is the standard anti-air air unit for the Protoss. It is a capable counter for all the smaller flying units in the game and is equipped with a rather interesting secondary ability called the graviton beam, which picks up ground units and makes them incapable of attacking, while allowing anti-air weaponry to attack them. This is especially effective when combined with...

...the Void Ray. Able to attack both ground and air units, the Void Ray utilizes an energy beam that doubles in damage every three seconds for the first six seconds, meaning it is much better against heavily armored targets (and buildings!) than lighter ones.

Immortals look like walking cocoons with legs and guns, and in many ways play like walking cocoons with legs and guns. Built as a counter to strong armor and strong weapons alike, the Immortals have a passive shield that caps incoming damage from most sources. That means Siege Tanks are virtually useless against an Immortal. Meanwhile, a small squad of marines will probably tear the unit a new immort-hole.

The Mothership is a unique unit, meaning you can only have one at any one time, and has a series of extremely potent abilities. First off, it can passively cloak any nearby units and buildings, letting you feasibly sneak an entire army beneath it. It can slow all movement, attack and casting speeds to half for thirty seconds. It can open up a vortex and paralyze and damage any units caught in its area of effect, and if its extremely slow movement has got you feeling blue, for a small cost it can instantly travel to any fully constructed Protoss building. Oh, and it's got an enormous amount of health.

Of course, what would be the fun in just looking at these units? They're lively! They need a place where they can run around and chase cars! We've seen a few of the multiplayer maps, and while a few old favorites make a comeback (Lost Temple, for example), there are plenty of brand new maps too. So far there are about eleven maps total.

In the two-player bracket we have Lost Temple (with a few tweaks and new features), Burning Rift, Blistering Sands (one of the longest two player maps), Quicksand, Scrapyard (built for a particularly fast game) and Steppes of War (a small map with a lot of upper tiers for good defense).

Designed for four players we have Phaeton and Scorched Haven (both for 2v2 team battles), Kulas Ravine (a very large map), New Antioch (with multiple paths into the starting bases), and the classic Lost Temple,

In addition, there's a 4v4 map called Bulken, with shared choke points and a ring of raised platforms around a central high-resource area.

Scattered throughout many of these maps are new landmarks called "xel'naga towers". When a unit nears a xel'naga tower, the tower falls under that player's control and illuminates the map in a large radius around the tower. As soon as the unit moves away, though, the tower becomes a neutral object again. Typically the towers are placed in strategic locations like the very center of the map, or adjacent to a chokepoint.

There are also new gold-colored mineral deposits, worth about 40% more per harvest than the regular blue minerals. These are typically placed in contested areas or areas that are extremely difficult to defend, and are designed to speed up the late game.

There are a lot of units and abilities that, as of writing, may or may not make it into the game, such as the Terran Cobra. There are also dozens of new abilities, both passive and active, and tweaks, across almost all the old that are still around. We'll do our best to keep you informed though.

Original credit : http://pc.ign.com/articles/105/1056577p1.html