Here is the full list of all 47 Sentinel 3: Homeworld achievements.
Kill 1,000,000 aliens
Unlock all commander abilities
Reach maximum commander level
Complete a classic assult level without upgrading any turrets
Classic map 6 has been completed in assault mode
Classic map 5 has been completed in assault mode
Classic map 4 has been completed in assault mode
Classic map 3 has been completed in assault mode
Classic map 2 has been completed in assault mode
Classic map 1 has been completed in assault mode
Unlock all Sentinel weaponry
Unlock all turrets
Kill 100,000 aliens
Reach wave 150 in endless mode on psycho difficulty
Fully upgrade an aerial slow turret
Reach wave 100 in endless mode on psycho difficulty
Complete mission 20 of the original campaign
Complete mission 19 of the original campaign
Fully upgrade a sniper turret
Complete mission 18 of the original campaign
Complete mission 17 of the original campaign
Complete mission 16 of the original campaign
Complete mission 15 of the original campaign
Fully upgrade a line laser turret
Complete mission 14 of the original campaign
Complete mission 13 of the original campaign
Complete mission 12 of the original campaign
Fully upgrade a flamer turret
Complete mission 11 of the original campaign
Complete mission 10 of the original campaign
Fully upgrade a booster turret
Complete mission 9 of the original campaign
Fully upgrade a beam turret
Complete mission 8 of the original campaign
Kill 10,000 aliens
Complete mission 7 of the original campaign
Complete mission 6 of the original campaign
Fully upgrade a missile turret
Complete mission 5 of the original campaign
Complete mission 4 of the original campaign
Fully upgrade a slow turret
Complete mission 3 of the original campaign
Complete mission 2 of the original campaign
Fully upgrade a bomb turret
Kill 1000 aliens
Fully upgrade a laser turret
Complete mission 1 of the original campaign