[Last weekend Blizzard brought its annual fan explosion BlizzCon back to Anaheim, CA. I desperately wanted to be there, to watch the latest GSL finals in person and catch a Foo Fighters show. More than anything, though, I really, really wanted to see all the new multiplayer changes in the new StarCraft II expansion pack, Heart of the Swarm. But alas, there's a lot of work to be done this time of year that makes it hard to get out of town. (Hey, have you read my Uncharted 3 review?)

Enter special contributor and friend of Giant Bomb Brian Leahy, a diehard fan of StarCraft II who did make it through BlizzCon and lived to bring us a wealth of info and analysis of all the new stuff Blizzard is working on. -Brad]

I haven’t been playing as much StarCraft II as I used to, opting to watch professional matches instead of brave the ladder, but my hands-on time with the current build of Heart of the Swarm’s multiplayer component has reenergized my love of SC2. It’s a breath of fresh air to have some new units and some fairly drastic balance tweaks, which have so far been unheard of in Wings of Liberty. HOTS is very much its own game, which lets Blizzard shift the power balance in a major way.

Kerrigan Is The Heart Of The Swarm In StarCraft II's First Expansion

But regular Zerg are here too!

I played nine games of multiplayer, three as each race, and while I won’t rehash the list of new units or tweaks (already written up elsewhere), I’m happy to share some of the cool things I experienced. Again, everything here is subject to change, and Blizzard will be conducting a full beta test of HOTS multiplayer, so anything you read here may be dramatically different by the time we see it next.

TerranA few Battle Hellions lay waste to a Zerg base full of lings.

Of the three races, I was least impressed with the Terran tweaks, but that could just be because my Terran game is trash. The Warhound is intended to fill the void now that the Thor has reverted to its classic “one at a time” super-unit role. The Warhound is basically the equivalent of the original StarCraft's Goliath with a few tweaks, and it completely rips up enemy mechanical units, making it quite good in TvT or TvP. Beyond that, it’s not that exciting. The Hellion’s new Battle Mode is a bit closer to the mark, as its higher damage and lower movement speed adds some situational strategy to the unit and gives it a bit more late-game usage against Zerglings or Zealots.

The Shredder is a very interesting unit, and this is one that I think will evolve during the beta. It’s got a lengthy eight-second deploy, but once it's deployed it deals constant damage to any enemy unit (not including buildings) in its circular range. But if any of your own units enter the field, it shuts off. However, this doesn’t include other Shredders, which means that if you can sneak two into the enemy mineral line and somehow manage to go undetected for 8 seconds, you can destroy an entire worker line in a little under two seconds. That’ll probably never happen at the pro level, but I can see this working wonders in the lower leagues. Beyond that, the Shredder should be good for area denial, especially when backed up by a Siege Tank line. It may help defend against Zerglings, Zealots, and Hellions early in the game, as well.

I didn’t really get to play around with any of the tweaked Terran units, but did go up against a boatload of Warhounds in a PvT and got steamrolled by them, so there may be some hope yet for this new toy.

Zerg

The biggest change to the Zerg is the complete removal of the Overseer, which had a few interesting spells, moved quickly without an upgrade, and was the Zerg’s only detection outside of the Spore Crawler. Gone! In its place is a new flying spellcaster called the Viper that currently rocks a trio of spells. One of them lets you make any unit a detector (including the Viper itself). Thankfully, the spell also pops a big goofy Overseer eye on the target unit so those DTs will know which unit to target to return to stealth. Blinding Cloud is a twist on Dark Swarm, a spell sorely missed from the Brood War days. Instead of negating ranged damage, it will reduce all attacks to melee range and prevent energy based spells. This is incredibly useful for advancing on the Terran and Protoss. Additionally, since the Viper is a flyer, it’s a bit easier to dart in and cast Blinding Cloud than you could Dark Swarm in Brood War. Oh, and the Viper can grab units and pull them up close, Scorpion-style, which is great for picking off powerful enemy units individually, even massive ones.

The Swarm Host gives Zerg a ground-based siege option of sorts.

The Swarm Host is a really interesting concept and basically amounts to a burrowing Brood Lord with a much slower spawn rate on its Locusts (the equivalent of Broodlings). Locusts can be manually spawned, or just set to auto-spawn with rally points. They only last a short time, but it’s long enough to close the distance on some bunkers, soak up Siege Tank shots, or otherwise harass an entrenched position. These are enabled with the Infestation Pit, so they’ll see much more mid-game use than the Brood Lord and should really help give the Zerg something else to do besides expand or throw expensive units against a defending player at that stage of the game.

Oh, and now Banelings can move while burrowed, Ultralisks can rush underground and pop up under a targeted location, and the Hydralisk finally gets a meaningful off-creep speed upgrade. This is the Zerg expansion, so I guess this all makes sense, but man, those are some major buffs. I’m really scared for my PvZ game.

Protoss

Ah, Protoss, my race of choice and currently the weakest race in the pro leagues. What does Blizzard have in store for my squad? Well, turns out it's two really interesting units and yet another flying capital ship that replaces the Carrier. In its place is the Tempest, which is basically a Protoss version of the Battlecruiser with a better air-to-air weapon. It requires the Fleet Beacon and sits at the end of the tech tree. It’s quite beefy and does decent damage to ground forces. Currently it will absolutely shred a Mutalisk flock, though, so it might find some use.

At least more players will soon be constructing their builds around the Stargate, because the Oracle is the harassment unit Protoss players have been missing. Sort of. The Oracle can be built straight from the Stargate, currently has no upgrades, and gets all three of its spells immediately. The first, Entomb, is amazing. It's an AOE spell that can block mineral fields from being mined unless the enemy waits for the lengthy duration to expire or attacks each patch one by one to remove the force fields. On most of the maps, I was able to shut down every mineral field in my opponent’s base in a single casting. The value of that ability speaks for itself.

Look at all those unusable minerals! LOOK AT THEM!

The other harassment spell, Phase Shift, can stun a building to effectively remove it from the game temporarily, which would prevent it from building and researching (or attacking in the case of defensive structures). The best use here is in PvZ. If you Phase Shift an enemy Roach Warren, say goodbye to the ability to hatch Roaches until it wears off. Preordain, the third spell, shouldn’t be ignored, either. It lets you tag an enemy building, granting vision around it for a set duration and also letting you see what that building is doing. For instance, you can see if that Starport is building a Medivac or a Banshee (though the tech lab would tell an experienced player it’s a Banshee). That sort of intel is invaluable at high levels of play.

Finally, the Replicant is a fun little unit that, while expensive, can lead to some creative uses. It’s built from the Robotics Facility for a hefty 200 minerals and 200 gas, and its only ability is to instantly copy a non-massive unit. Blizzard is still tuning what abilities the replicated unit will get, relative to your opponent’s tech level. Should you get Siege Mode if you copy a tank even if your enemy doesn’t have it yet? If not, you wouldn’t be able to research siege yourself, and then you’d end up with a un-siegeable tank. Hooray. I think a lot of tuning will have to go into the Replicant, but it definitely adds a good bit of depth to Robotics Facility play.

Finally, the Mothership gets the axe and the Nexus gains two abilities to compete with your valuable Chrono Boosts. Arc Shield is quite useful and functions as a great panic button, briefly turning any structure into a photon canon, though it can only damage light units. I heard whispers around the show floor of a quite deadly photon cannon rush using Arc Shield on the proxy Pylon to defend while the real cannons warped in, but I didn’t see it myself. The Nexus can also recall units from anywhere on the map back to itself for a whopping 75 energy (that’s three Chrono Boosts!). That's a nice new tool for the box and should make players feel a little safer about being aggressive in the early game, since they can bail out of an engagement if things are going badly.

I’m (massively) biased toward the Protoss as it's my chosen ladder race, but I was really happy with the changes here. I’m not yet sold on the Tempest, but I hate Mutalisks, so maybe I’ll come to love it in time.

Muta-hating Protoss players are probably going to love the Tempest.Some Random Things I Did

Here's a handful of memorable situations that came up in my time with all these new toys.

• While under attack by a Zerg force with Swarm Hosts, they burrowed and I didn’t have any detection. Thankfully, I could quickly use the Replicant to copy the enemy’s Viper and pop a goofy eye onto my Immortal, giving me instant detection and allowing me to see the burrowed Hosts.
• Now that Reapers regenerate their health while out of combat, I had a lot more fun harassing mineral lines with them, retreating, and coming back when they were all patched up. They lost their D8 Charge building attack, though, so it’s not all fun and games.
• As the Zerg, I was trying to break the front lines of a Protoss player with a Roach and Zergling force. I saw a few Immortals up on the high ground with my Vipers, so I positioned my Zerglings forward and snatched them down to the low ground to surround them. Then, when my opponent comes down the ramp with his Stalkers, I dropped a Blinding Cloud on them so they couldn’t hit my Zerglings until they closed the distance.
• The Terran’s Orbital Command is really powerful for building an economy. How about sneaking a Replicant in a Warp Prism to the enemy’s mineral line, copying an SCV, and escaping to go build my own Terran base elsewhere, complete with Mules. Yup.
• Similarly, if you can copy a single enemy unit (like a Siege Tank) and get it safely back to your base, you can continue to replicate that unit from the comfort of your own home.
• OK, one more Replicant story (they're really interesting). I built a Stargate to play with the Oracle and then added a Robotics Facility. I decided to mass Void Rays to exploit a lack of anti-air on my opponent's side. Instead of having to build a second Stargate, I can just pump out Replicants and Voids and copy the real deal. Double production, no extra buildings!
• My Terran opponent tried to use the new Thor against me. It hits like a truck, dropping Stalkers in two hits, but it still dies a bit too quickly to really find a place in the Terran lineup. (Don't forget you can only have one at a time now.) I’m really concerned this Thor change is just going to turn it into the next Mothership.
• Baneling bombs on mineral lines are already powerful. How about dropping them into the enemy’s blind spot and burrow-moving them into position first? Because, yeah, you can do that now.
• As a Terran against the Zerg, I was putting pressure on his natural expansion and was able to get a Shredder into position right at his ramp, drastically weakening the reinforcing Zerglings coming to defend the expo.

You can bet all this stuff is going to change in some fashion between now and the beta (and then change again before release), but it was really refreshing to play some games of StarCraft II with a ton of new options and some big surprises. It would be foolish to judge the eventual product purely on what was shown at BlizzCon, but I think Blizzard is on the right path with the new units and tweaks. As with all such massive balance changes, only time will tell if Heart of the Swarm will hit the right notes with players from professionals all the way down to comp-stomp versus-AI players.