Starcraft 2, Brutal difficulty walkthrough with commentary

Mission 4: The Evacuation

Your mission is to escort a bunch of helpless civilians across the map. Unlike your normal escort level, this is pretty easy. The civilians (once outside of the truck) do not have weapons, so the AI does not target them if you have marines nearby. There are 3 chrysalises on the map (locations in walkthrough) that you can destroy for Zerg research points. Your base never gets attacked, so don't worry about defense. The key to winning is to simply make a gigantic force of marines and medics.