Here is the full list of all 68 Tannenberg achievements. It takes around 15-20 hours to unlock all of the achievements on Windows.
Unlock all specializations for the Latvians.
Win 25 Gold Medals.
Get 50 artillery kills using trench phones.
Get the first kill in a match.
Get killed by bots 50 times.
Chop off someone's limbs with a sword.
As Frontovik, while crouched, get 3 grenade kills.
Kill 25 enemies with a HMG.
Kill 25 enemies with artillery as the Central Powers.
Used voice commands 50 times.
Exhaust all your revolver ammo without missing a shot.
Make 5 kills within the first two minutes of the match.
Club someone to death with binoculars.
Kill 25 enemies with artillery as the Entente Powers.
Kill 4 enemies with a single grenade or call in.
Fight in every weather condition.
Win 10 matches as the Entente Powers.
Win 10 games as the Central Powers.
Unlock all specializations for the Bulgarians
Used voice chat.
Unlock all specializations for the Infanterie.
Unlock all specializations for the K.u.K. Trupp.
Kill 4+ enemies in a capture zone.
Capture an enemy sector alongside 10 or more other people.
Get killed by your own grenade.
Have your entire squad agree on a vote to change the squad name or type.
Die from falling down.
Get 10 kills with swords.
Kill 3 people with a sabre in an enemy held capture zone.
Become cut-off in a sector.
Issue 10 command orders.
Call in Artillery or Recon from a sector.
Cut off at least 3 enemy sectors.
Playing as the Central Powers, capture the enemy HQ.
Get a kill from 150m.
Be the first to get killed by an enemy in a game.
Playing as the K.u.K, lose a battle in the Carpathians.
Playing as the Infanterie, win a battle in East Prussia.
Win a game with a points difference of 100 or less.
Complete a match on a night map.
Complete a match on a foggy map.
Check out the credits screen.
Unlock all specializations for the Roumanians
Unlock all specializations for the Cossacks.
Unlock all specializations for the Frontovik.
Start a private match.
Die 10 seconds after spawning.
Be part of the top scoring squad in a match.
Capture 10 enemy sectors.
Switch to other team when asked for autobalance.
Damage two enemies with one bullet.
Get 7 squad spawns on a single life as NCO.
Resupply your ammo.
Kill an enemy while shooting through an object.
Kill 10 people with a heavy machine gun in a single life.
Kill 5 NCO's in a match.
Kick a bot off of a heavy machine gun.
Shoot an enemy while being suppressed or shaken by artillery.
Perform a role switch.
Using a sword, kill an opponent who is also using a sword.
Get a kill while injured.
In a single life, take damage from melee attacks and gun shots from a player or players, before being killed by someone entirely different.
Visit every sector in a Maneuver match.
Make a successful retreat
Kill an enemy soldier manning a heavy machine gun with a head shot.
Complete a match on a snowy map.
Playing as the Entente Powers, capture the enemy HQ.
Have a look at the overview map.