There are 35 anomalies and they don't reset over a playthrough. So if you run out, it's game over and you completely reset, which is actually needed for an achievement. Some anomalies are deadly and can kill you. Being killed by the zombies, zombie walking man or the ceiling skeleton appears to reset the anomalies.
The goal is to walk the length of the hallway and spot things that are out of place. At the end of the hall there is a doorway and a lever. If you spot an anomaly, you pull the lever. If not, simply walk through the door. The loop starts again, and you see if anything has changed on the new loop.
Firstly, I experienced a couple a texture glitches. One where the red line on the floor was further away from the wall than usual. Then another with water damage and lines down the wall on the right, next to the exit door. These are NOT anomalies! These glitches can occur with real anomalies on that loop, in which case you should pull the lever. But NEVER pull the lever if these texture glitches occur, but without an anomaly from the list. I've included screenshots of each glitch so you know what to ignore.
The anomalies spawn in completely at random, so I've ordered the list by the location in the hallway that the anomalies appear in for ease of searching. If the anomaly doesn't appear, simply move down the list to the next one. If nothing from the list appears, then walk through the exit door to the next loop. The sign on the wall will let you know if your decision is correct by going up by one with every successful decision. Doing 12 in a row will unlock all but one of the achievements.
01 - (DEADLY) The lights are out with glow in the dark paint on the floor and there are zombies lining the sides and one behind you, hunting you. Go all the way to the lever without stopping. If any of the zombies touch you, you reset. It's best to stick to the paint on the floor as much as possible. This anomaly starts from the open doorway, but it very rarely happens early in the game. It usually only spawns in after several loops.
02 - Double lines on the ceiling panels next to the first light.
03 - The poster on the left changes.
04 - Monsters in first painting on the left wall.
05 - (DEADLY) The walking man is stood in the alcove to the right and is a zombie. Go all the way to the lever without stopping. The walking man is fairly slow as a zombie but if he touches you, you reset.
06 - A man is peeking through the first door on the right.
07 - The poster on the right wall, just across from the previous door, is changed.
08 - A dead version of the player is in the first room on the right behind a window.
09 - There are numbers in the red line on the ground on the left side, across from the room with the man in the bed. For some reason, they wouldn't load in properly for me and just appeared as a smudge (as shown in the screenshot). It's supposed to be a skull, 13, 13, 13, 13 and then another skull. But if it appears the same as in the screenshot for you, that IS an anomaly so pull the lever.
10 - A small creature bleeding from inside the AC on the right wall next to the room with the man in the bed.
11 - A man hanging in the next room.
12 - A man crushed in a machine in the same room.
13 - Station 13 written on the right wall instead of Station 18.
14 - The walking man is walking noticeably faster.
15 - The walking man has a red eye.
16 - (DEADLY) A skeleton hanging from the ceiling with blood dripping on the floor. When you make it halfway down the hallway, the skeleton will drop and chase you. It's quite speedy so go to the lever, pull it and go through the door asap.
17 - There are a bunch of monsters in the second painting on the left wall.
18 - The caged bird near the woman in the wheelchair is dead.
19 - The woman is eating the bird.
20 - Monster sat on a chair inside the dark room on the right.
21 - Two demonic girls in the first painting on the right wall.
22 - Amputated foot instead of fire extinguisher next to the poster of the old woman.
23 - Poster on left wall is changed.
24 - Blood across the hallway, leading to a giant rat inside the now open double doors.
25 - Decapitated head in the bin across from the double doors.
26 - The man behind the large window is smashing his head into the glass in the last room.
27 - Numbers and writing on the right wall just before the corner.
28 - Alien on the wet floor sign.
29 - The word rodent is written on the soda inside the vending machine.
30 - There is large spider inside the vending machine.
31 - Blood on the floor and bloodied hand prints on the door near the vending machine.
32 - Poster on right wall is changed.
33 - There's a bunny with blood on it immediately after the last poster, sat inside one of the planters.
34 - A chalk outline of a body on the ceiling near the last light.
35 - A body being dragged inside the last door on the right.
With each consecutive correct decision, you'll unlock:
ANOMALIE 1Don't make mistakes reporting anomalies 1 consecutive times.
ANOMALIE 2Don't make mistakes reporting anomalies 2 consecutive times.
ANOMALIE 3Don't make mistakes reporting anomalies 3 consecutive times.
ANOMALIE 4Don't make mistakes reporting anomalies 4 consecutive times.
ANOMALIE 5Don't make mistakes reporting anomalies 5 consecutive times.
ANOMALIE 6Don't make mistakes reporting anomalies 6 consecutive times.
ANOMALIE 7Don't make mistakes reporting anomalies 7 consecutive times.
ANOMALIE 8Don't make mistakes reporting anomalies 8 consecutive times.
ANOMALIE 9Don't make mistakes reporting anomalies 9 consecutive times.
ANOMALIE 10Don't make mistakes reporting anomalies 10 consecutive times.
ANOMALIE 11Don't make mistakes reporting anomalies 11 consecutive times.
ANOMALIE 12Don't make mistakes reporting anomalies 12 consecutive times.
Only one achievement left now and that is to deliberately go through the game unsuccessfully until you've seen every anomaly spawn in for that run and causes a game over. So this one is a little on the buggy side. In order to get it to trigger the easiest, I would recommend exiting the game and loading in fresh from dashboard and then try for it. Simply go through the loops without touching the lever. You'll need to go through a minimum of 35 loops and it'll probably take around half an hour. It's best to try and keep track of the number of loops you've done so if it gets to an unreasonably high number like 70, you'll know that the game is bugging out.
If the game bugs out then try the alternate method of following the list and marking off the anomalies as you see them. Report a few of them, then ignore a few of them to reset the counter on the wall. Continue doing this until you reach the end of the list and trigger the game over cutscene. The achievement should finally pop then.
Important to note for both methods, if any of the deadly anomalies appear, you have to survive them or the anomalies will reset, which will essentially start you from the beginning again.
Here is the list without the screenshots in-between so you can copy and paste them into notepad to check them off.
01 - (DEADLY) The lights are out with glow in the dark paint on the floor and there are zombies lining the sides and one behind you, hunting you.
02 - Double lines on the ceiling panels next to the first light.
03 - The poster on the left changes.
04 - Monster in first painting on the left wall.
05 - (DEADLY) The walking man is stood in the alcove to the right and is a zombie.
06 - A man is peeking through the first door on the right.
07 - The poster on right wall, just across the previous door, is changed.
08 - A dead version of the player is in the first room on the right behind a window.
09 - There are numbers on the red line on the ground on the left side, across from the room with the man in the bed.
10 - A small creature bleeding from inside the AC on the right wall.
11 - A man hanging in the next room.
12 - A man crushed in a machine in the same room.
13 - Station 13 written on the right wall instead of Station 18.
14 - The walking man is walking faster.
15 - The walking man has a red eye.
16 - (DEADLY) A skeleton hanging from the ceiling with blood dripping on the floor.
17 - There are a bunch of monsters in the second painting on the left wall.
18 - The caged bird near the woman in the chair is dead.
19 - The woman is eating the bird.
20 - Monster sat on a chair inside the dark room on the right.
21 - Two demonic girls in the first painting on the right wall.
22 - Amputated foot instead of fire extinguisher next to the poster of the old woman.
23 - Poster on left wall is changed.
24 - Blood across the hallway leading to a giant rat inside the open double doors.
25 - Decapitated head in the bin across the double doors.
26 - The man behind the large window is smashing his head into the window in the last room.
27 - Numbers and writing on the right wall just before the corner.
28 - Alien on the wet floor sign.
29 - The word rodent is written on the soda inside the vending machine.
30 - There is large spider inside the vending machine.
31 - Blood on the floor and bloodied hand prints on the door near the vending machine.
32 - Poster on right wall is changed.
33 - There's a bunny with blood on it immediately after the last poster, sat inside one of the planters.
34 - A chalk outline of a body on the ceiling near the last light.
35 - A body being dragged inside the last door on the right.
FIREDRun out of opportunities to report correctly in one day.
Congrats on another 1000g!