Here is the full list of all 25 Tiny Troopers achievements. It takes around 6-8 hours to unlock all of the achievements on Windows.
Collect 10 Medicrates in Zombie level
Revive fallen squad members 10 times in Zombie level
Kill 50 Enemies with Airstrike
Kill 50 Enemies with Rockets
Beat Chapter 3
Kill 50 Enemies with Machine Gunner
Kill 50 Enemies with Grenades
Kill 50 Enemies with Delta Force
Fully Upgrade Your Squad
Destroy 10 Tanks
Beat Chapter 2
Get a full squad in Zombie level
Lose 5 Troopers to Mines
Beat Chapter 1
Order 10 items from HQ
Use Airstrike to Kill 3 Enemies At Once
Use one of each heavy weapon on a single mission
Destroy 10 Towers
Earn 200,000 Command Points
Collect 25 Dog Tags
Lose the first mission
Kill 100 Enemies
Kill 100 Zombie chickens
Open a Gate in Zombie level
Complete the Tutorial