Here is the full list of all 49 Trepang2 achievements.
Eviscerate Dr. Emerson’s corpse
Collect all intel docs
Kill an enemy with a flashbang impact
Acquire all weapon parts
Throw a TF27 soldier into the helicopter blades in Site 14
Throw an enemy into the vent in the first combat encounter in Site 14
Use every bullet in a pistol magazine to get headshot kills
Complete all campaign and side missions on Very Hard difficulty or higher
Complete all campaign and side missions on Extreme difficulty or higher
Complete all campaign and side missions on Rage Mode difficulty
106 is reborn
Stealth kill an entire squad without anyone becoming alerted
Collect 50% of all intel docs
Let the world know
Break The Cycle
Cycle 106 comes to an end
Completed Level: Horizon HQ
Complete all campaign and side missions on Hard difficulty or higher
Kill the Horizon CEO
Complete Level: Site 83
Complete Level: Site 32
Destroy 100 beer/wine bottles
Complete Level: Crash Site
Complete Level: Oil Rig
Complete Level: Kellington Colliery
Complete Level: Gunnarson Complex
Complete Level: Jorvik Castle
Kill the Patriarch
Acquire the dual wield serum
Destroy 1000 cultist books
Slide into an enemy and grab him while he’s ragdolled
Kill an enemy with a tomahawk
Complete Level: Iron Dragon Data Center
Shoot an enemy’s thrown grenade, killing him with it
Kill an enemy by shooting through his helmet with a DMR
Complete Level: Pandora Institute
Kill the Mothman
Collect the Syndicate coin “XCV”
Grab an enemy, throw and kill him with a headshot
Kill an enemy with a headshot on final bullet in the mag
Escape from Site 14
Kill all TF27 soldiers in Site 14
Alert an enemy by shining a flashlight from behind, shoot him before he turns around
Kill a heavy soldier
Use a weapon bench to customize a weapon for the first time
Shoot an enemy while he’s thrown as a hostage grenade, detonating his grenade
Kill 3 enemies with 1 grenade
Collect the Syndicate coin “CV”
Execute your first hostage