Blizzard has just posted their three official Starcraft II mods. There’s a Protoss cooking game called Auir Chef, a head-to-head match-3 called Starjeweled, and a co-operative zombie survival mode called Left 2 Die. This latter mode is an adaptation of the Outbreak campaign mission.
At night, you and a teammate are tasked with protecting your base against waves of infested terrans. In order to survive, you’ll need to use defensive structures like bunkers and coordinate your defenses against the invading zerg armies. You’ll also want to watch out for special zerg units such as the Kaboomer and Stank that can perform unique and powerful abilities capable of overwhelming even the strongest front lines.
During the day, the attacks on your team’s base will cease, giving you and your teammate time to train additional units and take them out to destroy infested terran settlements scattered across the map. It’s also a good idea to continue building up defenses during the daytime so you can survive the merciless onslaught of zerg that swarm your base at night.
There’s even an endless night mode where the goal isn’t to win, but to survive as long as you can.
Although these are technically beta, I’ll bet you dollars to donuts they’re ten times more playable as the typical beta in Starcraft II’s poorly organized morass of custom maps. It’s kind of cute when Blizzard suggests that to play these modes, “simply [sic] go to the Multiplayer tab in StarCraft II and look for the custom games window”. That’s like saying to defeat communism in Southeast Asia, “simply send in a few military advisors and defeat Ho Chi Minh”. A far better way to find these modes is to type the name into the search box and hope the actual mod floats to the top.
Go here to read more details on the game modes, including screenshots.