Currently it is still unclear what exactly is needed but so far it turns out that you have to choose mostly negative, lie to Eddy in Chapter 3 and choose at the end Alyson's memory. I recommend to do this achievement together with the
on your second playthrough. You need 2 playthroughs to get all achievements.
There is no indicator in the game how many negative choices you needed, so for the safe side I recommend to replay! the game from chapter 1 (not isolated mode!) and be negative as possible. You can skip a lot of cutscenes and save a lot of time.
Here is a list of all my negative choices during my playthrough. The remaining choices should not be any effect to any achievement in the game (as example Tessa at Graveyard)
Chapter 1Ferry- I don't care
Ronan House - Puzzle Door- Examine the door
- Open (door handle)
- Break down the door
Ronan House - Balcony- Must be nice to forget
- Is something wrong
- That book changed everything
- Couldn't find the time
- Stop making it about you
Store- Choose Alyson's memory
Store - Talk with Tessa (don't get any clues)- We remembered details
- It's time to talk now
- April 2004
- You were mad she bailed on you
Police station- Eddy did his best for me
Chapter 2Ronan House - Outside- Choose Alyson's memory
Car Stop (Telephone conversation with the realtor)- Let's do it
Police station (After Archive Room)- Are you kidding me?!
- She was struggling!
- So you called child services
- That's bullshit, Alyson!
- No, its not that easy
Store (After the plushie Battle)- You're swell too
Graveyard - Totem- Choose Tyler's memory
Ronan House - Docks- Even after what I did for you?
Chapter 3Eddy's House - Talk with Michael- Don't tell Michael about the Memories
- Won't do any good
Police station- I wanna forget
- I can't move on
Fishing with Michael- We're too different
- I was the kid who killed his mom
Ronan House - Barn- Break the Box with the crowbar and don't solve any puzzles
Ronan House - Dock- Choose Alyson's memory (Marry-Ann threatened Tyler)
If you need a visual guide I have create a 100% video guide for this game with all achievements, all collectibles and all choices. The second playthrough / bad choices start at 35:32 (Timeline in spoilers)
Chapter 1
*** Spoiler - click to reveal ***00:00 - 00 - Info
00:16 - 01 - The Crafty Goblins
01:12 - 02 - Choice
01:31 - 03 - This Is Despicable Achievement
02:14 - 04 - We Need To Talk Achievement
03:12 - 05 - The Mad Hunter
03:56 - 06 - Crafty Goblins Achievement
04:33 - 07 - The Wise Princess
04:56 - 08 - Choice
05:29 - 09 - Full Confession Achievement
07:58 - 10 - The Pious Pelican
09:23 - 11 - Hacking 101 Achievement
10:33 - 12 - The Ice King
11:16 - 13 - Choice
Chapter 2
*** Spoiler - click to reveal ***11:27 - 01 - Kick Me Achievement
11:52 - 02 - The Big Frog
12:20 - 03 - Moo'd Changer Achievement
13:26 - 04 - Guess Who? Achievement
14:20 - 05, 06 - Choices
14:52 - 07 - The Stalwart Moose
15:21 - 08 - State Your Emergency Achievement
17:11 - 09 - Choice
17:43 - 10 - The Mangy Muskrat
18:22 - 11 - Remember Strange Vampire Achievement
19:10 - 12 - Sharp Shooter Achievement
20:09 - 13 - Choice
21:15 - 14 - The Very Old Beaver
21:41 - 15 - The Moon Hag
22:16 - 16 - Choice
Chapter 3
*** Spoiler - click to reveal ***22:24 - 01 - The Secret Keeper
24:00 - 02 - Choice
24:14 - 03 - Mailbox Bandit Achievement
26:05 - 04 - Choice
26:17 - 05 - Just One Fix Achievement
27:14 - 06 - The Old Bear
27:44 - 07 - Fish all the Fish Achievement
28:51 - 08 - Choice
29:53 - 09 - The Gold Lady
30:48 - 09 - And Everything In Its Place (The Gold Lady is part of this Achievement)
31:42 - 10 - The Princess' Lost Treasure (The Gold Lady Puzzle is part of this Achievement)
33:35 - 11 - Box Code (Good Choice if you do all puzzles which is patz of Princess' Lost Treasure Achievement)
33:59 - 12 - Choice
34:29 - xx - Epilogue
Second Playthrough