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