Here is the full list of all 21 Alien Shooter TD achievements.
Wipe out 500000 aliens.
Complete 35 different missions in an expert mode, earning gold shields.
Complete 35 different missions on hard level, earning gold stars.
Complete 25 dif1ferent missions in an expert mode, earning gold shields.
Complete 25 different missions on hard level, earning gold stars.
Complete 25 different missions on medium level, earning gold stars.
Complete 5 different missions on any difficulty level using only mines and explosives.
Kill the Boss in mission №40 on hard level of difficulty.
Train any soldier up to level 30.
Kill the Boss in mission №35 on hard level of difficulty.
Complete 5 different missions on any difficulty level using only Tactical Forces.
Recycle 100 weapons.
Complete 25 different missions on easy level, earning gold stars.
Mission earnings: 500000
Equip all troops with rare, unique and legendary weapons. Standard weapon should not be equipped.
Complete 25 different missions on any difficulty level.
Complete 5 different missions in an expert mode, earning gold shields.
Mission earnings: 100000
Complete 5 different missions on any difficulty level.
Mission earnings: 10000
Wipe out 1000 aliens.