Playing With Anyone As Your Main Character, Reach An Ending.
There Are Probably About 40 Different Endings To Your Adventure. (There are a few more, but they dont count)
-Dying is (usually) Not One Of Them.
Survive To Claim Victory With A Full Crew Of Four, and This Achievement Will Pop!
The Key To This. Is Picking One Of The Faster Endings, And Making Sure You Make Additional Food With Your Crafting Machine.
Sending Out Your 4th Guy On Expeditions, Also Cuts Down On Food Consumption, As He Does Not Eat When Outside.
Goodluck!