(There's a great guide in Chinese language here:
http://steamproxy.net/sharedfiles/filedetails/?id=261148865 ) ;)

If you haven't played the game at all or have only played a few chapters, I strongly suggest closing this guide and get back to playing ASAP :P
This little guide contains spoilers for you, then. You would miss out on a lot of great stuff, too!
Also, you might not get what I'm talking about :P

If, however, you are missing only a couple of achievements and are willing to take the risk of getting your gameplay experience spoiled, please do continue to read :)

This one requires that you save right before you follow the "Queen of Maggots" deeper in her home.
This is, so you can do both of them in one playthrough ;)
You can, of course, do both on seperate playthroughs, though :P


Once the "Queen" asks you, either choose "I'll do it my way" (thus refusing her offer) or do anything she asks and follow along :P

These two should be fairly easy ;)

Listen carefully to Liz, when she's talking to you.
You might be able to save her life....

The correct answers are:

• ‘Yeah, she smoked a cigarette & burned in bed’
  
• ‘Stripper’
  
• ‘On Valentine’s day’.

This achievement might be a reference to Portal - which I love :P
Thanks to folks (not only but especially) of this thread: http://steamproxy.net/app/253110/discussions/0/648813728487565769/ - especially http://steamproxy.net/id/frankokomando and http://steamproxy.net/id/hachach19 :)

The solution to this achievement is actually quite simple, once you've got the hang of it :P
The crow has a riddle for you in chapter 2 - two dolls and two doors.
You can only ask ONE doll ONE question to get the ONE right door for this achievement!

Solution: Ask one of the dolls (which one doesn't matter) the following question: "Which door would the other doll tell me through" (or something like that)
Then choose the door that is NOT hightlighted.
Done :)

Explanation:

Messaggio originale di Alex:

The idea is to pick the question that will 100% force the dolls into pointing out the right or wrong door for you, and by asking the question above, they will always point out the wrong door.
This is because the lie of a truth is a lie, and the truth of a lie is a lie, so no matter what, the wrong door will be highlighted.

PS:
If you ask any of the other questions, you still won't be able to tell if the door they highlighted is the right or wrong one, so the game will punish you for asking a question that didn't point out the right/wrong door for certain, which results in both doors being wrong.

There are THREE options to get out of the "lair" of Doctor X in chapter 2.

• build a spear (1st weapon in order to be able to attack the Doc)
  
• build a mace (2nd weapon in order to be able to attack the Doc)
  
• Don't kill the Doc, just get out of there.

You can easily collect all the stuff needed, it's rather linear.
The only thing you could miss is in the room to the absolute right, with the flickering light ;)

In order to get both achievements in one playthrough, just save right before killing the Doc, with either weapon :P

In chapter 3, there are two powers on the bottom left.
One is ANGER, one is RELAXATION (at least that's what I like to call them :P)

The goal with this achievement is to never get ANGER to raise to the bottom, but RELAXATION ;)
For this to happen there are several things to avoid and/or to do!
In chronological order:

• Pay the meter, before even trying to switch the light on
  
• Check the bills, before getting the money out of the purse
  
• check the burger label and use the microwave correctly
  
• don't use milk, but whitener
  
• collect all the stuff needed for the scarecrow and put it together on the balcony, BEFORE heading out to smoke and drink coffee

Just use some logic and SAVE ;)

There's a GREAT quick walkthrough for this achievement, too :P

Please note that this achievement MAY interfere with your progress on "Unbreakable", but if you play "Unbreakable" near perfect, it may not :P Be sure, to have saved ;)

To get this achievement, simply say the magic phrase "Go ♥♥♥♥ Yourself" to Bryan, when he's at the door, complaining about your cats and you playing piano. It is a relief, actually :P

When you're trapped in pest control guy's home, leave it and continue to walk to the right, until the achievement pops up ;) It will look like it's endless, but this is how it works ;) Don't give up :P

Yes, it's that easy :)

The key here is (at least it was for me) to save after every step you make :P

While doing chapter 4 just normally, do NOT get killed by Gladys, the wife of the pest control man.
The thing is, as soon as she sees you, she will kill you.
So:

• Save after every step, just in case
  
• Don't just go in the shed, SNEAKPEAK :P
  
• I was surprised by her in the kitchen a couple of times, so save at least before you enter the kitchen and continue to the right - especially when having done a couple of tasks already
  
• Once Gladys is dead, the achievement will pop up :)

I've struggled a little myself, to get this one right :P
The folks of http://steamproxy.net/app/253110/discussions/0/648813728511827242/ figured it out :) Special thanks to http://steamproxy.net/id/frankokomando , he put the solution out there :)

Once in chapter 5, and having reached the moment when you're YOUNG Susan, do the following:

• Answer the phone - it's the "Lover"
  
• Be rude and neglect liking him

Choose the following options (THESE MIGHT NOT BE ACURATE, BUT YOU WILL GET IT, WHEN YOU SEE THEM :P):

• "We went to dinner on time. That's it."
  
• "It was just lipstick"[...]
  
• "The kisses (lips??) were like nettles"[...]

Again, these options might not be acurate (help me out here, guys? :P)
Once you dump your "lover" that way, the achievement will pop up :)

Credits for this goes to the folks of this thread http://steamproxy.net/app/253110/discussions/0/648813728094363077#p4 and especially http://steamproxy.net/profiles/76561197960358489 (Benny Baroni) for solving this :P

The solution to this achievement is actually quite simple.

Once in chapter 6, do the following in chronological order:

Messaggio originale di Benny Baroni:

• Clear flat 1, 2, 3, and 5
  
• Do the whole babysitter thing in flat 8 and cut the power, etc.
  
• After Jesse leaves pick the lock of his flat (7), walk in and pick up the mask, now turn around and leave.
  
• Go to the basement and assemble the dress, go through the cutscene with brian (in flat 6)
  
• Now Jesse's apartment will be the only one without an "X" on your map (aside from Susan/Mitzi's flat).
  
• Go to his apartment and use the extension cord
  
• Get back to flat 1 to plug it in, then back up to check his computer

Whatever you do (and there are a lot of different methods/options here :P), SAVE right before opening the shoe box the old man gives you in chapter 7 :P
Use this savegame to get back and do the other achievements ;)

"Scared of Dying" // "Sacrifice" :
(Hold tight to your gas mask) // (Give your gas mask to Mitzi)

Whatever option you choose, YOU will live.
If you keep the mask for yourself, continue and do "Revenge" ;)
If you give the mask to Mitzi, you can decide between "A Ruthless Killer" or "I Care About You"! You have one last chance to save right after you give the mask to Mitzi, which makes this last choice a lot easier ;P !!!!


"A Ruthless Killer" // "Revenge" :
(Let Mitzi kill The Eye of Adam) // (Kill The Eye of Adam yourself)

Just either let Mitzi kill the guy already (the room will explode!) or kill him yourself (mentioned above)


"I Care About You" :
(Prevent Mitzi from killing The Eye of Adam)

Just talk Mitzi out of it - I believe the chronological order is unimportant, key is that you conclude with a sentence like "I care about you..." - If you have done everything right, this achievement will pop up :)


Another hint:
There's this scene in chapter 7, where you go back to the "Queen of Maggots".
There you will be offered a choice: Blow out the left, the right or no candle.

This is especially important, if you're working towards "A Flower That Bent Towards The Sun" (see there :P)

I'll tell you what the 7 things are that you need to do to achieve the "golden ending" and therefore this achievement.

These are in chronological order:

• Chapter 1: Refuse the offer of the "Queen Of Maggots" ("I'll do it my way")
  
• Chapter 2: Prove to Liz that you've listened (get at least question 2 and 3 right)
  
• Chapter 2: Solve Crow's riddle and get the secret gift
  
• Chapter 3: Don't have a breakdown
  
• Chapter 7: Give Mitzi the gas mask
  
• Chapter 7: Refuse to blow out the last candle
  
• Chapter 7: Don't kill and don't let Mitzi kill the Eye of Adam

PLEASE NOTE:
You have to do all these requirements in one playthrough, to be able to get the achievement.
I't doesn't suffice if you've done all of them at seperate times.
However, different save games will work!

So, if, for example, you save after every thing that is needed and give the savegame right after the gas mask to anyone - he/she will be able to complete the achievement by completing the last parts ;)

Credits go to Grim himself (http://www.adventuregamestudio.co.uk/forums/index.php?action=profile;u=7565) :)

Again, I've merely put the info together - it all began in the http://www.adventuregamestudio.co.uk/forums ;)
Thanks for reading - enjoy this AWESOME game :)
Please let me know, if I should post a guide for anything else ;) maybe a complete achievement guide?