This guide is aimed for achievement hunters and players that like to 100% games.
Sadly currently you can't 100% this game normally due to 1 achievement being broken and unobtainable (to my knowledge and experience)

Duration to "100%": around 3hrs (depending if you gonna go sight seeing)

You can squeeze each playthrough to around 15 minutes. You will have to play at least 9 full runs to get all ending related achievements. Don't forget that you can skip dialogues with right mouse button.

here is a default map for you:
Lower you will find maps filled with all important stuff

Select Tutorial in menu and follow the story.

When starting New Game, select that you want Nightmares Game Mode (Longer Prologue) first, you can also select this via Chapters -> Nightmares. If you get stuck just try to locate the birds flying above

You don't have to do dumpster eating mode, there is no achievement dependant on this odd mechanic. Once you're ready for playing first run, you'll get all these eventually, these are unmissable:
Here is a map of points where you progress in chapters, 0s are where you start in a chapter. Birds are pretty much useless now, so if you don't know where to go just follow colored numbers depending on each chapter:
In certain parts of chapters police cars/officers can force you to restart whole chapter, so be sure to stay away from them.

Things to note for chapter 1:
You can choose between cafe or casino to get a drink, this is why they both are the same number.

*Intermission isn't covered on this map since it is pretty straight forward.*

Things to note for chapter 3:
depending if you took pills or not you might get "teleported" to number "?"

After you finish your first ending, here are the specifics on how to reach other ending related achievements

(any ending at hotel) During the last cutscene when you're getting closer to the edge press right mouse button

Here is a map of additional objects/people/route that you have to use during certain chapter in order to get specific ending:

Once you get all endings, you'll unlock this

When you reach the hotel (normal C5-1), stay in entrance room downstairs for 5 minutes.

Map in previous section shows placement of the Key you need for this achievement to unlock

Start New Game, once in room, check the revolver multiple times, first with LMB, then RMB twice and that's it.

At anytime during chapters 2 and 4 press X.

After you finish all endings, go to Chapters -> Epilogue, then go to where it all started

VD Massacre Achievements - for these you have to go Chapter -> VD Massacre:
You know where is the knife at this point, go get it.

Find 4 couples press X near them, here is map to help you:

Select Extra in Main Menu, then follow through first door on right, you'll end up in early version of streets, it is fairly close on the right, follow the pictures to a dead end then interact small ball on the ground:
Once you are in different place keep jumping from platform to platfrom until you get to the other side, be careful, sometimes you can keep falling down forever forcing you to restart the game completely (not much of the loss, since this is easy to get to anyway).

Game becomes unresponsive upon selecting Chapters -> Two Dark Nights, so you can't get this one, at least I didn't find any way.