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