Here is the full list of all 45 Enemy Front achievements.
Obtain First Sergeant rank
Obtain all medals in Deathmatch, Team Deathmatch and Radio Trasnmission modes
Finish game on Casual difficulty level
Finish game on Medium difficulty level
Finish game on Expert difficulty level
Paint all Polish resistance symbols on levels that happen in Warsaw
Collect all secrets
Destroy all vehicles inside the workshop in 'Final Victory' mission
Kill all enemies inside the V2 factory
Collect all rocket parts in 'Fire from the Sky' mission
Rescue Dietrich from POW Camp without raising any alarm
Rescue prisoners from POW camp
Kill 50 Germans and destroy all armored vehicles in 'Home Army Victorious' mission
Save Home Army soldier in the hospital
Kill 10 enemies during 'Loud Sound'
Collect 30 secrets
Destroy all enemy planes using anti aircraft cannon in 'Fortress at Oscarborg' mission
Kill all snipers on top of PAST with a sniper rifle without reloading it
Destroy the cable car in 'Winter in Vemork' mission
Use commanding officer inside PAST as a human shield
Collect all Blyskawica radio station parts in 'PAST Assault' mission
Kill 20 enemies using explosive environment objects (Singleplayer)
Kill 3 SDKFZ gunners without destroying the vehicle
Set and detonate explosives on the enemy truck in 'Officer hunt in the Loue Valley' mission
Destroy all enemy vehicles inside ruined castle in 'Sabotage in the Loue Valley' mission
Collect 15 secrets
Play 50 Multiplayer matches
Defend back of the church without using HMG in 'Siege of St. Cross' mission
Kill 25 enemies using mounted HMG (Singleplayer)
Help all resistance members in 'French Resistance' mission
Throw back 3 enemy grenades (Singleplayer)
Collect 5 secrets
Rescue the priest with a single shot in 'First Victory' mission
Get into the prison without raising alarm in 'First Victory' mission
Kill an officer and blow up the armory with one shot in 'First Victory' mission
Kill two enemies with one bullet (Singleplayer)
Lure 5 enemies by throwing stones
Take enemy officer/soldier as live shield, then kill 3 enemies
Perform 100 Headshots in Multiplayer mode
Become the most valuable player in 10 Team Deathmatches
Win 5 matches in Radio Transmission mode
Win a match in every Multiplayer mode
Play all Multiplayer modes
Win a Deathmatch round without dying
Play any Multiplayer match