Here is the full list of all 30 Tiny Troopers: Global Ops achievements.
Defeat 100 enemies in total
Acheive a score of 50,000 in a mission
Complete the tutorial
Defeat all of the chickens in the HQ
Defeat 500 enemies in total
Defeat 1000 enemies in total
Achieve the max main trooper rank
Unlock a full 4 trooper squad
Upgrade a primary weapon to max level
Purchase all abilities and weapons
Complete chapter 1
Complete chapter 2
Complete chapter 3
Complete chapter 4
Complete chapter 5
Complete chapter 6
Complete all chapters
Collect every dogtag in every mission
Collect 50 medals
Collect 100 medals
Collect 250 medals
Acheive a score of 100,000 in a mission
Acheive a score of 250,000 in a mission
Finish any mission in under 60 seconds
Complete 25 Missions without losing any troopers
Achieve a mission shot accuracy above 90%
Achieve a mission shot accuracy below 10%
Change a troopers head 50 times
Change a troopers body 50 times
Customise all 4 squad members