Here is the full list of all 47 Sentinel 3: Homeworld achievements.
Kill 100,000 aliens
Complete mission 20 of the original campaign
Complete mission 19 of the original campaign
Complete mission 18 of the original campaign
Complete mission 17 of the original campaign
Complete mission 16 of the original campaign
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
Complete mission 15 of the original campaign
Complete mission 14 of the original campaign
Classic map 4 has been completed in assault mode
Classic map 3 has been completed in assault mode
Fully upgrade a line laser turret
Fully upgrade an aerial slow turret
Classic map 2 has been completed in assault mode
Complete mission 13 of the original campaign
Fully upgrade a flamer turret
Complete mission 12 of the original campaign
Complete mission 11 of the original campaign
Complete mission 10 of the original campaign
Complete mission 9 of the original campaign
Complete mission 8 of the original campaign
Complete mission 7 of the original campaign
Complete mission 6 of the original campaign
Fully upgrade a booster turret
Fully upgrade a sniper turret
Classic map 1 has been completed in assault mode
Fully upgrade a beam turret
Kill 10,000 aliens
Complete mission 5 of the original campaign
Fully upgrade a missile turret
Complete mission 4 of the original campaign
Fully upgrade a bomb turret
Fully upgrade a slow turret
Complete mission 3 of the original campaign
Kill 1000 aliens
Complete mission 2 of the original campaign
Complete mission 1 of the original campaign
Fully upgrade a laser turret
Unlock all turrets
Unlock all Sentinel weaponry
Unlock all commander abilities
Reach maximum commander level
Kill 1,000,000 aliens
Reach wave 100 in endless mode on psycho difficulty
Reach wave 150 in endless mode on psycho difficulty