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