Here is the full list of all 20 Terminal squad: Sentinel achievements.
Complete level 200.
Kill 10 000 enemies.
Deal 100 000 damage.
Collect 100 000 000 credits.
Complete 50 tasks.
Complete level 100.
Complete 20 tasks.
Complete level 50.
Spend 120 minutes in battle.
Complete 10 tasks
Kill 1000 enemies.
Collect 100 000 credits.
Spend 60 minutes in battle.
Complete level 10.
Spend 30 minutes in battle.
Deal 1000 damage.
Collect 1000 credits.
Kill 100 enemies.
Complete level 300.
Deal 100 000 000 damage.