Here is the full list of all 40 The Walking Dead: Season 2 achievements. It takes around 8-10 hours to unlock all of the achievements on Windows.
Completed Episode 5: "No Going Back"
Found your way through.
Reached the terminus.
Made it through to morning.
Reached the other side.
Stopped for the night.
Took a breather.
Made it out alive.
Completed Episode 4: "Amid the Ruins"
Got back on the road.
Survived the attack.
Reached the museum.
Found the Observation Deck.
Learned new survival skills.
Returned to the meeting place.
Got separated from the group.
Completed Episode 3: "In Harm's Way"
Gave what you got.
Invited some friends into the compound.
Committed larceny.
Got beaten down.
Made it through your first day.
Witnessed a murder.
Arrived at your new home.
Completed Episode 2: "A House Divided"
Settled things with a new friend.
Made it to the ski lodge.
Found a way across the water.
Met someone on a bridge.
Left the cabin.
Talked to a stranger.
Helped someone through a difficult time.
Completed Episode 1: "All That Remains"
Headed out with the group.
Got what you needed.
Took care of yourself.
Arrived at the cabin.
Met new people.
Found a campsite.
Arrived at the shore.