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