Here is the full list of all 36 Crossfire: Legion achievements.
Destroy three enemy Corebases within 30 second of each other
Win 10 games with the highest combat score
Completed the Campaign on Hard Difficulty
Completed the Campaign on Easy Difficulty
Win a game with infantry only
Completed Crossfire: Legion Mission 15
Completed the Campaign on Medium Difficulty
Completed Crossfire: Legion Mission 14
Completed Crossfire: Legion Mission 13
Completed Crossfire: Legion Mission 12
Completed Crossfire: Legion Mission 11
Completed Crossfire: Legion Mission 10
Completed Crossfire: Legion Mission 9
Completed Crossfire: Legion Mission 8
Completed Crossfire: Legion Mission 7
Completed Crossfire: Legion Mission 6
Completed Crossfire: Legion Mission 5
Completed Crossfire: Legion Mission 4
Completed Crossfire: Legion Mission 3
Completed Crossfire: Legion Mission 2
Completed Crossfire: Legion Mission 1
Completed all Coop missions on Intermediate Difficulty
Completed all Coop missions on Expert Difficulty
Completed all Coop missions on Standard Difficulty
Completed all Coop missions on Advanced Difficulty
Win 10 Standard Mode games as Black List
Win 100 Standard Mode games as Black List
Win 100 Standard Mode games as New Horizon
Win 100 Standard Mode games as Global Risk
Win 10 Standard Mode games as New Horizon
Win 10 Standard Mode games as Global Risk
Enter 1000 units into stealth
Kill 1000 units using commander abilities
Teleport 1000 units
Win a game with every commander in the game
Win 10 games with the highest economic score