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