Mission 6: The Dark Templar

Conditions for winning

• Destroy all Protoss units and structures
• Kerrigan must survive
• Take Kerrigan to the central island to meet Tassadar alone

Conditions for losing

• All your structures are destroyed
• Kerrigan dies

After you start, immediately make a new base to your east, and then later, if you wish, to your west. Those two spots are full of minerals and are vacant. Once you're secured both areas as well as your main base, start buildings Zerglings by the bunch, from Hatcheries, which by now you should have 5 or 6.

Once you have around 5 full groups of Zerglings, Move them all south until you come across a natural bridge, and a whole bunch of Dragoons and a few Photon Cannons. Have your Zerglings destroy the Dragoons and sweep up northeast to the other small Protoss base, if you wish.

This other one is somewhat more difficult, as it has Reavers which can kill Zerglings rather quickly. Once you've defeated those small Protoss bases, build Guardians until you have 12 or 24, and send them, inching forward and all focused together. You should be able to take out anything ground, and have Mutalisks as backup if there are air resistance.

After you've eliminated all Protoss units and structures, put Kerrigan in an Overlord and send her to the central island.