Blizzard had a playable demo of StarCraft 2 running at Leipzig, and Kotaku's Michael McWhertor had a chance to sit down and spend some time playing the Zerg. The Zerg weren't available in previous demos; the Protoss and Terran campaigns were showcased earlier. GameSpy took the opportunity to interview two Blizzard employees about what people can expect from the game. Gameplay footage is also available which shows a Terran vs. Zerg battle. Blizzard PR rep Bob Colayco had this to say: "One thing that's new, as you go through the campaign... you know, normally in RTS games how they start you off with a couple of units and then it's like, 'Okay, two missions later we're going to give you tanks...' One of the things we're looking at doing with StarCraft II's campaign is putting the choice more in the players' hands. So maybe you like dealing more with infantry? You can purchase those upgrades and make your marines and other infantry stronger. Or else you'll save up the credits you get from the missions to get tanks sooner than you normally could."