This can be done on any ‘Terror’ mission. The following are the 3 categories and requirements for an ‘excellent’ rating:
- Aliens killed: Kill all aliens on the map
- Operative lost: No squad members can be killed
- Civilians rescued: At least 75% rescued.
The hardest part of this achievement will be rescuing civilians, as the aliens will not waste any time killing them. Unlike some other missions, you will need to play offensively, taking the fight to the aliens quickly. Try and focus most of your attention on killing aliens, instead of rescuing civilians as you can always double back or use a weaker squad member to rescue them later. When engaging aliens, particularly Chryssalids, make sure you focus all your fire on one and kill it, before moving on to the next. In Terror missions, having three wounded aliens is much more dangerous than one enemy at full health.
As long as you have received a rating of ‘excellent’ in all 3 categories, the achievement will unlock during the mission results screen.
TIP: Outfit your squad with ‘assault’ and ‘heavy’ classes as these are better suited to close quarter combat, and (your assault soldiers) can utilise the ‘Run and Gun’ perk. Also to make this achievement easier, outfit a squad using your most experienced soldiers.