This guide will be updated in the coming days, I'll add more screenshots and hopefully I'll be able to update 'For your personal collection', 'Fast food', 'Creep' and 'Bloodlust'.
So obviously, this guide will contain spoilers, probably a lot of em. Be aware that some content will be shown that will probably spoil some events during the game! Aside from that, despite doing some grinding, I have not figured out all achievements yet, and I hope the community can contribute to it!

Enjoy!

You need to turn the volume on the DJ equipment up, by interacting with the equipment on the left from the DJ at the beach. You will get this achievement naturally, as you need to turn up the volume at the DJ table to lure a crowd away who block the path towards the next box.

You will also get this achievement by natural progress, for me it popped as soon as I used the password to enter the door at the start of the game.

When you find the bacchanal.mod area, take a bottle of wine at the bathtub and bring it to the riddler, the guy wearing a cat mask.
He is located at NAX-05, which if you approach bacchanal.mod from the front, is located to the right. Drop the wine in the box with a pink R . Riddler will flee and the achievement will pop!(If you drop it in the left box, he will kill you)

I got this after completing the rites mural, since you will pass out after three beers in the hallway where The Beast goes on a rampage, just so you can reach the next area. But off course, you can get this earlier. Just keep chugging some alcoholic beverage and eventually, you will pass out and it will pop.

When you are at the beach in the beginning of the game, you will reach some portapottis at the third box. The potti at the right front can be openend, just open it, step inside, close the door and the achievement will pop.

You will get this achievement naturally if you follow the 'main story', just do all tasks at all boxes and when you have added all stones to the walls, it will pop.

Just follow the main story and this will pop at the end.

Now this is one of the first achievements for not following the main story line and working towards the second ending. When you complete tasks at boxes to obtain stones to complete the rite ritual, you can eventually return to the beach(first section of the game). I myself could return to here after obtaining stone 1, 2 and at least 1 colored stone, didn't matter which one. Just slap the crowd blocking the door KO, and you can pass through the door. At the back of the terrain in a little tent, your old friend CD(screammask-guy) will be waiting for you and attack when you are in reach. He will steal your phone and the achievement will pop. Keep in mind that by doing this you can NOT obtain all boxes, photo's and achievements related to the main story in this playthrough, from this point on.

Achievement for obtaining the second ending, after following the story towards the 'I thought we were friends' achievement, just keep progressing the storyline you end up in after, and it will naturally pop at the end.

I got this during the main storyline, approach the monster and try to slap him or throw something at him(Thanks to Shindragan for confirming this), and this will pop. Keep in mind you can lock yourself out of a no-death run by doing this, if the monster manages to grab you.

You can obtain this one at the second area, the rave itself. Somewhere in between Liber::MASS and bacchanal.mod or a bit behind bacchanal.mod is a box that's not connected to the rite. You can pick up the signal too, it's called Siduri's Lament Just keep looking between these boxes and you will eventually stumble upon it. At this box, connect and just read or scroll through the conversation, it will pop after this.

You can get this as soon as you connect to the second box in the second area, Da3dalus. From the start, literally where you enter the area, go right and keep heading forward, eventually you will stumble upon it. You can get this until you complete the rite, however, getting caught by the TLK(the guys with bird masks) and them dragging you towards it, will cancel out the achievement. These guys start chasing you around as soon as you collected 4/5 stones for the rite.

Thanks to Shindragan for making clear what this achievement is about You need to share the same photo in 7 different threads. Seven is the number. Just keep sharing all pictures you have in all threads, it will probably pop for the photo of CD(screammask guy), since that is the first photo you obtain and will be able to share.

When following the second story, as soon as the beast possesses you, start the slaughter. You do this by bashing B/interaction button, which will be shown as you asking help from the ravers, but it causes you to hit them. It's unclear how many kills you need, for myself I needed around 50 to get this, for others it might be less. It doesn't seem to stack, so if you didn't get it the first time(like me), the second time you also need to get as much kills as you can.
Thanks Shindragan for contributing information about the amount

Following the second storyline: at some point you will get to an area with a hole in the middle of the ground and a stairway. Just go up the stairs and follow the hallway. Eventually, you will see the altar and a group of worshippers to you left, hard to miss!
Thanks to Shindragan for making clear where the altar is

To get this achievement, you need to collect all boxes in the game. There is a fair amount, I will do my best to list all of them:

First area:
Cedar_synapse
Anonymous_Sign
PAN---UMBRA
N-tropy
CARN_4_ALL
pr0.-v1.d-3nce.

To be honest all the boxes at the first area are fairly easy, follow the main story line and they're impossible to miss.

Second area:
M1M1R_wake
Da3dalus
Liber:MASS
bacchanal.mod
NAX-05
M1M1r_sleep

Except for the Siduri's Lament box, you will also get all of these boxes naturally by progressing the main story.

Siduri's Lament is the box you need to find for the lover's quarrel achievement. For me it was always somewhere left-behind from the bacchanal.mod.

Third area
Hope==end:
This one is the only box in the game that is easily missable. It is located in the hall where The Beast starts a massacre. Don't touch the alcohol at the stands before you find this box! Drinking will make you pass out sooner than usual to warp you to the next area, hence why 'Bottoms up' is easier to obtain here.

Egregore++Manifest
Box on an altar where you will spawn after drinking beer at the hall, can't miss this one.

Lovi4t4r$bind
Right in front of you when you enter a maze where you encounter the beast.

Steps of Marduk
Hard to miss, keep following the main story and it will be right in front of you.

At first I was looking how to farm this at the beach or the rave during the rite. Don't even bother, for some reason clusters of ravers counted as one person. You can farm a few at the second area by jumping back to the beach and back and forward. The crowd blocking the door will respawn every time. However, after a few times these guys will also stop counting towards this achievement.
If you pick the second storyline, see 'I thought we were friends' achievement, you can slaughter around 120 ravers at the end of the story. Seems awfully bold to completer the second storyline 4 times for this achievement.

No, the answer to this one is the hall at the third area where The Beast goes ham. Just keep running around while he slaughters all ravers. If he's done, just let him kill you and repeat. It will pop when you either get killed or when you enter the next area and the game saves(Thanks Shindragan for adding this).

Take a picture of deceased Oedipa.
When you reach the maze at the Lovi4t4r$bind box, you need to follow the right path. Just go straight, at the end to the right, you will see Oedipa's body laying dead against the wall. Take a picture and the achievement will pop!

Need confirmation!!!
By following the achievement description, you'd have to get through the second and third area without getting knocked out or killed. There are some crucial points at this game, where you need to be on your toes.

Second area
When solving the riddle at NAX-05, do NOT put anything in the left box and NOTHING BUT wine in the right box.
After collecting 4/5 stones for the rite, avoid any TLK(bird mask guys), you can recognize them by the blue glowsticks. Just run as fast as you can towards the quarantaine zone, see 'Self-isolation' achievement.
When encountering the raver whose face is covered with black puss and blisters, just run. You will recognize him from the cutscene at the end of the first area, when you obtain the password. He is very slow and his hits do not instakill, but he will try to get to you for sure!

Third area
At the beginning of the hall, when The Beast goes rampant, get as fast as you can towards a stand with beer that's a fair length away from The Beast.Keep chugging and you will be fine.

When you reach the labyrinth where the beast is crawling around, take the left hall and watch from a distance when The Beast will go right. Be ready to run for the steel ramp or the exit when you get spotted, however, as long as you stay to the left and you are patient, this won't be a problem.

When reaching the upwards stair in rows of three, just sneak to the stair at the left. The Beast always took these first at my playthrough. From then on, I could sneak all rows of stairs on the left, while The Beast took all stairs on the right. I highly recommend to always take the left ones, since The Beast sometimes turned around on the right stairs and went down suddenly. Eventually, he always turned down at the top. On the right side at the top, you can see the raver with the laughing mask at the end at some king of altar. THIS IS A TRAP. A door will shut down when you approach him, and if The Beast happens to be at the top right stairs, you are screwed, Go left, the hall will turn immediately right, just keep following this one.

You can also get this by following the second storyline. By doing the second you avoid being followed by the tlk and you can choose to avoid the NAX-05 riddle. You will only have one maze encounter with the beast, where any raver inside the maze can transform into him and chase you. In my opinion, he is easier to avoid in this maze, cause you can hear and see the transformation, and make some meters before he can chase you. Aside from that, I had a glitch multiple times! When he started chasing me, I'd run towards the start and try to connect with the box(which you can't, since CD stole your phone). When I did this, the beast froze and wasn't unable to unfreeze for a minute or so.

There is a total of 11 pictures in the game that need to be taken for this achievement, be aware that some that are part of the main storyline, especially in the third area, that do apparently not count towards this.
The ones that counted for me towards this achievement seem to be:
First area
Photo of CD(screammask guy)

Photo of Ari(Question mark guy)

Photo of Oedipa(Bloody eyes girl)

Photo of TLK graffiti

Photo of TLK(Guys wearing bird masks)

Photo of Laughing mask guy

Photo of password(I AM WILLING)

Second area
Photo of stone wall(rite)

Photo of manuscript

Photo of Phix(Cat guy)

Third area
Photo of deceased Oedipa(Bloody eyes girl)


If you do it in this order, the achievement will pop when you reach the next save point.