Here is the full list of all 23 Frontline Tactics achievements.
Knowledge is power!
Swiftly defeat the enemy.
First successful mission turn boys to men.
Win some missions to get feet wet.
Win a lot of missions.
Pepper more than one target with bullets.
Unlock a little of everything.
Crossfire is good. More is better!
Use cover and survive longer.
Kill! Kill! Kill!
Unlock everything.
Defeat enemies of flesh and bone.
Kill multiple enemies in a single burst.
Grow your squad.
Deploy and extract a full team.
Perform slice and dice kills.
Defeat enemy elite troops.
Grenade fragments makes enemies bleed.
More skills are better than few.
Dual wield-r-us.
Horde a lot of credits.
Buying credits is totally OK!
Blind and stun enemies.