Here is the full list of all 40 The Walking Dead: Saints & Sinners - there are Chapter 2: Retribution achievements.
Play JB's final sermon
Kill 15 walkers with the sawed-off
Scavenege 10 items found only at night
Complete a full day of scavenging (one day and one night)
Collect all the weapon recipes in Retribution
Kill 15 humans with the Esteemed Mortal
Hit a grenadier's grenade out of the air with a baseball bat
Kill 11 humans with the grenade launcher
Kill a grenadier with their own grenade
Kill all the Dissidents
Kill 10 total Eradicators, 5 living and 5 undead
Beat Retribution
Complete all the Trade Network Orders
Establish your first Exile Foothold
Kill an Exile leader in every map
Kill 20 enemies with the grenade launcher
Put on walker guts while in stealth during the night
Kill 20 Tower soldiers
Perform 20 headshots while using laser sights on a weapon
Kill Father Carter
Kill 10 humans with the elephant gun
Kill 50 enemies with the chainsaw
Kill 15 walkers with the SMG
Return Maxwell's book to Whistles
Complete all of Sonny's requests
Give Sonny the picture of he and Henri
Kill 15 walkers using the sap gloves
Kill 15 walkers and 15 humans using the sap gloves
End the reign of the Pawn King
Kill 10 enemies with a silenced weapon without being detected
Complete all of Father Carter's requests
Survive your first encounter with the Axeman
Decide the fate of the Axeman
Collect every demon statue and bring them back to the bus
Destroy all the speakers in the speakeasy
Complete all of the Dissidents' requests
Complete all of Whistles's requests
Scavenge 10 items off of bodies/walkers during the night
Kill Whistles with an explosive
Complete all other achievements