I'll be going through all of the unmissable story achievements first, and then get into the more nuanced achievements that you may need to be purposefully trying to get. This guide is split into 2 parts. This is part 1.
Unmissable
This achievement is for waking up with fragmented memories after the crash of the Cassandra.
Unmissable
This achievement is for following Salim's trail.
Unmissable
This achievement is for dreaming of Paris.
Unmissable
This achievement is for carrying on with life, despite Salim's fate.
Unmissable
This achievement is for following the pilgrim's trail to take refuge in the fort.
Unmissable
This achievement is for exploring the inner fortress and speak to the doctor.
Unmissable
This achievement is for firing a cannon at the fortress gate.
Unmissable
This achievement is for taking time to talk with an unborn child.
Unmissable
This achievement is for finding a way through the ruined cistern.
Unmissable
This achievement is for traveling through the desert.
Unmissable
This achievement is for taking a walk in the park.
Unmissable
This achievement is for escaping the shadow.
Unmissable
This achievement is for activating the alchemist's device.
Unmissable
This achievement is for draining the life from a crew member.
Unmissable
This achievement is for activating a portal between worlds.
Unmissable
This achievement is for operating a scanning device and learning of a child's illness.
Unmissable
This achievement is for failing to reach a child, separated by deep waters.
Unmissable
This achievement is for reaching the doctor.
Unmissable
This achievement is for giving birth to a daughter, only to lose her.
Unmissable
This achievement is for completing the story.
Unmissable
This achievement is for leaving your daughter in the care of a god, and being reborn. While in the throne room, you’ll need to set your daughter back into the crib and walk out to be turned into a harvester.
Unmissable
This achievement is for sacrificing everything to cast down a god and end suffering. For this you’ll need to take your daughter with you and inject all 3 side room areas with the poison you got in a previous area. Once all three are done you’ll kill the god and in turn, also kill yourself and your baby.
Unmissable
This achievement is for escaping to Paris with a daughter that must now be cared for. This is the best of the endings and is achieved by taking your daughter with you, running to the exit of the throne room, and using the teleporter outside to escape.