Safe Haven (Achievements) | Campaign - Colonist missions SC II: WoL Guide
Last update: 11 May 2016
Safe Haven:
Destroy the Protoss Nexus, destroy the Purifier Mothership, stop the first, second and third terror fleet
You Shall Not Pass!:
You need to save three colonist encampments, including the one in your base. Some simple calculations lead to the conclusion that you can sacrifice two. You can complete this mission while depending on the power of the Viking alone, however you do need to be fast about it.
Start building those all-around airborne units from the start, adding a Reactor to the Starport in the first place. Place two or so Bunkers to protect the base and fill them up with Marauders and cheap Marines. Such a set should be quite enough, however you will probably have to face some hard moments. You can increase the defence later on, once you're rich enough.
Having a couple Vikings ready, head on to the nearest Protoss Nexus (they power the force field of the Purifier, which is the main target here). Destroy the two Prisms which power the Cannons, defending from a pair of Phoenixes beforehand. Land on the nearby cliff [1] and destroy the headquarters from up high, while in assault mode. Repeat the process with the middle base [2], looking out for the Colossus and Stalkers.
The lowest encampment has the strongest defence, with an Archon, Carrier and a Void Ray. Try to precisely eliminate the defendants, while avoiding an open fight. Attacking from the north-west seems like a good idea [3], as from there you can lure out the enemy airborne units into a one-on-one fights.
Overall, try not to get involved in unnecessary fight during the three invasions, but try to focus on attacking the Nexuses. Keep on adding new ships to your squad, while investing in upgrades in the Armory. Return to base from time to time to repair your machines (or keep SCVs somewhere behind).
Also don't hesitate from helping the colonists in chasing the attackers away, as this way you will receive resources, helpful in the process of producing new Vikings. Keep in mind that in the end you also have to destroy the Purifier, which will probably welcome you with a vortex (your units will temporarily disappear).
My Precious:
The above description pretty much fits this achievement as well. You just need to act a bit faster and keep in mind that on higher difficulty settings, there's a bit more units in the Protoss bases. An additional Archon is waiting for you in the south, or a Templar which will summon a Psi Storm on sight.
The key to victory is the first phase of the mission. Try to lose as few units as possible during destroying the first two Nexuses, while assembling a squad to attack the third base and fight the Purifier.