Here is the full list of all 40 XCOM: Chimera Squad achievements. It takes around 60-80 hours to unlock all of the achievements on Windows.
Complete all versions of each Faction’s Takedown mission over multiple campaigns.
Win the campaign on Impossible difficulty.
Buy 20 unique Scavenger Market items in a single campaign.
Replace an Agent mid-mission with an Android.
Complete a mission with only one Agent left standing.
Hack an enemy Android with Patchwork and trigger Self-Destruct.
Move a VIP with Shelter’s Relocate and Torque’s Tongue Pull.
Relocate the same unit with Shelter and his ghost in one turn.
Kill an enemy with Axiom while Berserk.
Use every Agent in at least one mission.
Clear an entire encounter during the Breach turn.
Complete an encounter by only dealing damage with melee attacks.
Launch a mission with no human agents in the squad.
Win the campaign.
Complete the Sacred Coil Investigation.
Reach max rank with all Agents in a single campaign.
Capture a Ronin.
Complete every Spec Op at least once in a single campaign.
As Godmother, activate Overtime and down an enemy on both turns.
Use every type of Breach point.
Use Torque to Tongue Pull an enemy into poison.
Complete 20 Assembly Projects in a single campaign.
Fully upgrade an Android.
Complete all of one Agent’s class training.
Complete the Gray Phoenix Investigation.
Use Claymore to detonate a Shrapnel Bomb with another explosive.
Use Verge to do 10 or more damage with one Mindflay.
Have Rank 3 Field Teams in all nine districts.
Use Zephyr to hit 3 or more enemies with one use of Crowd Control.
Capture a Praetorian.
Use Blueblood to hit 3 or more enemies with one Phase Lance shot.
Have 8 Agents in the squad in a single campaign.
Unlock all Field Abilities.
Equip an Epic Weapon.
Complete the Progeny Investigation.
Complete an objective with an action from Terminal’s Cooperation.
Have Kinetic Armor on all 4 squad members at once.
Capture a Sorcerer.
Complete a mission without killing a single enemy.
Complete the tutorial.