Here is the full list of all 13 Zombie Wars: Invasion achievements.
First upgrade towers
Complete level with 3 stars on Hard Mode
Complete level with 3 stars
Complete All Levels !
Complete all levels Hard Mode
Complete all levels with 3 stars
Upgrade all towers level 5
Upgrade Minigun to level 5
Upgrade Ice Tower to level 5
Upgrade Tesla to level 5
Upgrade Flame tower to level 5
Upgrade Aircraft to level 5
Upgrade Sniper to level 5