Here is the full list of all 42 Kontrakt achievements.
Complete all achievements.
Unlock an alternate ending.
Complete the game.
Inspect every item.
Complete chapter 3.
Unlock all gun modifications.
Unlock the basement.
Kill 30 enemies with a UZX.
Beat level 6 in Borderman.
Beat level 4 in Borderman.
Beat level 2 in Borderman.
Kill 15 enemies with a Savior.
Unlock all sentinel echoes.
Complete chapter 2.
Kill 30 enemies with a Subs-5.
Kill 30 enemies with a Kapus T4.
Kill 50 enemies with a Kata 7.
Die 100 times.
Kill 15 enemies with a sawed-off shotgun.
Kill 50 enemies with a Behemoth.
Kill 15 enemies with a Myalot X2.
Kill 10 enemies with a Davi-gale.
Complete chapter 1.
Die 50 times.
Kill 50 enemies with a KA-74.
Perform a jump kill.
Get a triple kill with any weapon.
Perform a slide kill.
Shame, shame...
Play Borderman.
Kill 10 people in under 30 seconds.
Kill 10 enemies with a Formal 14.
Unlock a sentinel echo.
Love interrupted...
Unlock a gun modification.
Hint: gramaphone.
Complete a contract.
Die 10 times.
Kill 10 enemies with a Kompakt M8.
Get a double kill with any weapon.
Kill an enemy while using sense.
Perform a melee kill.