Here is the full list of all 26 Outpost: Infinity Siege achievements.
Save a missing operative.
Open a locked container using a lockpick.
Exploit Kronos' weakness and make him kneel down.
Clear level [Into the Abyss] for the first time.
Clear level [Outpost 11] for the first time.
Clear level [Rescue] for the first time.
Clear level [The Nebulas] for the first time.
Clear level [Seraph] for the first time.
Reach an Outpost value of 10000.
Reach an Outpost value of 50000.
Reach an Outpost value of 100000.
Reach level 30.
Recover items worth 3000R in a single Recovery.
Complete 100 Recovery Days.
Complete all research projects.
Unlock all departments.
Defeat 5000 enemies by hitting the weak spot.
Defeat Kronos for the first time.
Defeat Crius for the first time.
Explore 10 different landmarks.
Deal more than 5000 damage in a single instance.
Run at the human speed limit.
Defeat a Bomber using melee.
Do not touch the ground for more than 30 seconds.
Have a single round cost of more than 150.
Complete recovery after 15 Exploration Days.