Upon reaching the main menu.

Welcome Back!
• Welcome to Roots of Insanity Remake!

I've been told this achievement doesn't unlock in the current version 2.1.18. The Welcome Back! section at the end has details on which version to rollback to.

Go into the options and change the difficulty to NORMAL. It defaults to Just Story difficulty.

• "Zombie Hunter" requires you to kill every zombie without being killed yourself. I was only able to unlock this on a second playthrough, despite it being identical to my first playthrough. I've listed all the zombie encounters (that I found) in the game, so don't miss any.
  
  
• I only realised later that whether cabinets and lockers contain items is random. I'm not going to change the guide, but don't expect to find the exact items as me and feel free to open any cabinets and lockers not mentioned.

Exit your office.
Your office is "Dr. Riley McClein" [SIGN].
Next door is a "General Ward" [SIGN].

• There's an achievement for looking at 5 signs. There's ~20 signs in the game, so missing this one is unlikely.

Go down the hall, left at the fork (right is dead end).
Behind the counter is a [LIVE TV].

• An achievement requires looking at 5 working TVs, but it's impossible to know how the game considers a TV "looked at". I put my crosshair over all parts of the TV including the antenna and the achievement still only unlocked at the 6th TV. There are 8 TVs in the game, so you can miss a few.

Enter the door to go to the courtyard.

Enter the security booth down the path that goes right. Find a [KEY].
Use the key to enter building B.

The First Victim
• Find out who killed the nurse.

Read [NOTE_1] by the nurse's body.
[BATTERIES] on the desk. [MEDICINE] on the chair.
Go around the fallen lockers to trigger a jump scare.
Enter the room on the right. See the [LIVE TV].
Return to the body.

Enter the room on the left. Read "Waiting Room" [SIGN].
See the [LIVE TV] on the floor. [MEDICINE] in a fridge.
Return to the body.

Go around the fallen lockers again.
Immediate left is a room with two [LIVE TV].

Crossroad ahead.
Read "Operating Theater" [SIGN] ahead. It's locked.
Left goes to a zombie QTE and hallucination.
Right leads nowhere.

Go down the hallway left of Operating Theater (no zombies).
First room on the left is the "General Ward". Cabinet with [MEDICINE] inside.
Next room down the hall has the "Library" [SIGN].

Curious
• Read 5 signs.

Enter room right of the library for a hallucination.
Continue down the hall past the library and your way back will be blocked.

On the left is another "General Ward" [SIGN]. Locked.
Continue down the hall. Kick the zombie on the floor.
Enter the library.

On the right wall is a cabinet with [MEDICINE]. Plus [MEDICINE] and [BATTERIES] on the chairs.

Lucky
• Find two cabinets with medicine in them in succession.
  (If you didn't find medicine in the General Ward earlier, you won't get the achievement here. Just keep opening cabinets and it'll unlock eventually.)

Walk past the tables for first zombie attack.

Zombie Killer
• Kill the first zombie you face.

Interact with a book on the shelves at the back. It's highlighted in red with the lights off.

Go downstairs.
Open next door.
Continue past the showers. [BATTERIES] on a chair.
Round the corner. [BATTERIES] in a locker.
Exit the room.

Into the hall. Room opposite has nothing.
Zombie QTE down the hall.
Continue down the hall to the generator room.

Swap your knife for the [AXE] by the blue fuel tank.
Behind the first generator is a "Backup" [SIGN].
Behind the second generator is a "Basement" [SIGN].
[KEY] on a desk on the right.
[BATTERIES] on a chair.

At the back is a room with a generator. Inspect it for the next objective.
The generator has a "Floor 1" [SIGN].
Return to the previous room. Find the [FUNNEL] in a locker in the dark corner.
Use the funnel on the generator.
Return to the room with the funnel. In a corner on the other side is an [EMPTY FUEL CAN].
Exit the room and fill the can at the blue fuel tank at the end of the hall.
Fill the generator. Pull the lever.
Exit the generator room.

Go right and open the door for a shortcut back to the stairs.
Return through the library to the locked General Ward.

Past the gurneys is a cabinet with [MEDICINE].
Go right past the cabinet. Zombie ahead.
Continue into the next operating room.
After the hallucination, there's a [HEALTH +10] vial on the bench on the left.
Exit through the only door.

Across the hall is another "General Ward" [SIGN]. Enter.
Zombie QTE ahead.
In the room at the end, read [NOTE_2] on the desk.
[MEDICINE] in a fridge.
Walk around the room and exit through a hole in the wall.

See the "Custodial Room" ahead. Enter.
[BATTERIES] on a chair to the left.
Jump down the hole in the floor at the back.

Zombie ahead.
Exit the room and down the hall.
Inspect the first door on the left. Needs key.

Enter room on the right. Zombie attack after the short scene.
Exit.

Continue down the hall. Three zombie attack ahead.
Enter the room at the end.

Look left and read [NOTE_3] on the gurney.
Through the other broken wall and down the hall.
Enter the room at the end.

You have two minutes to save the patient.
On the left is [BATTERY +15] on the chair.
Enter the room at the back.
The [PATIENT'S MEDS] are on a chair on the left.
In the middle of the room is [HEALTH +10], [ENERGY +25], [HEALTH +10], [ENERGY +25], [ENERGY +25].
There's another [ENERGY +25] on a smaller table.
On the right is [MEDICINE] on a chair and more [MEDICINE] in a cabinet.
Give the patient his medicine.

The Hippocratic Oath
• Save a patient who was about to die.

Four zombies attack.

After the fight, the door at the back right is unlocked.
Halfway down the hall is a [KEY].
Exit the hall to be in the room that was on the right earlier.
Exit this room and unlock the one opposite.

Continue down the linear path to the Unknown Courtyard.

Explore the woods. There's two zombies, a [BATTERY +15] on a table.
Your destination is the fire in the distance.
Automatically pick up [NOTE_4] and [GUN].

Continue down the hill for a firefight.
After the battle against four zombies, grab a [KEY] from a body by the graves.
Run up the stairs and enter Floor 1.

[MEDICINE] in a cabinet on the left.
[MEDICINE] on a chair.

In the next room, two zombies attack after a hallucination.
The zombie closest to the entrance is playing dead.
[BATTERIES] in a locker on the right.

There are three paths ahead.
The right connects to the centre with two zombies (playing dead) and [BATTERIES] in a locker hidden in a dark corner. Another zombie on the floor in the centre room itself.
In the "Waiting Room" on the left is a [LIVE TV], [KEY] on the desk and [ENERGY +25] on a chair.

Let Us Know If You See Anything
• Look at 5 working TVs.
  (As mentioned earlier, this achievement is a little confusing and may not unlock here. There are two more TVs in the game and hopefully it'll unlock properly, otherwise a new playthrough will be required.)

Zombie will attack as you exit.
Go through the gap in the lockers left of the three paths.

Ahead is a zombie playing dead.
First right leads to bathrooms. Just one zombie.
Skip the hole on the left and enter the "General Ward" [SIGN] on the right further on.
In a room at the back is a zombie on the floor, [MEDICINE], [BATTERIES], [AMMO], [BATTERY +15].

Return to the hole in the wall.
[MEDICINE] in a fridge.
Enter the only door.

Approach the zombie in the small room on the left for a surprise.
Continue through the room back into the hallway.
The room you just came from has a "Dr. Riley McClein" [SIGN].
Ahead is [NOTE_5] on the desk.
Down the hall to Floor 2.

Behind you is a "Floor 2" [SIGN].
[MEDICINE] on a chair on your right.
Left around the stairs for [BATTERY +15].

Proceed into the middle of the room for a hallucination and fight against two zombies.
[BATTERIES] in a locker in the darkness on the right.
A zombie playing dead by a locked "Operating Theater".

First door on the left has [HEALTH +10].
By the next hole in the wall is [BATTERIES].
Inside is [MEDICINE] in a cabinet, a [LIVE TV], [ENERGY +25], [HEALTH +10], [HEALTH +10], [ENERGY +25].
Walk towards the wandering doctor for a zombie attack.
By the hole in the wall is a zombie playing dead.
Inside the hole in the wall is [BATTERY +15] and a zombie further in.
Room further in has [MEDICINE] in a cabinet.

Return to the large room and enter the room at the end of the hall for a quick scene.
Read [NOTE_6] on the gurney.
Zombie attack next room. [HEALTH +10], [BATTERY +15], [HEALTH +10] on tables.
Cross the hall into the next room.

Zombie and [MEDICINE] in a cabinet in the back.
Down the previous room is [ENERGY +25] on the gurney.
In the room at the end is [MEDICINE] in a fridge and [AMMO] on a chair.
Exit the room and into the next with the "Meeting Room" [SIGN].

[BATTERIES] in a locker.
[NOTE_7] on the table.
[BATTERIES] and [BATTERY +15] at the back.

Heal up before going down the next hall.
Around the corner you'll be grabbed by a zombie and lose your weapons.
This initiates a chase sequence.
Sprint down the hall, turn left and jump over the gurney.

Immediately to your right on a table is a [KEY].
Proceed into the large room head and into one on the left.
Inside is [HEALTH +10]. Open the next door and go downstairs.
Run forward and into the hole on the floor.

Stay in the room you start in and wait for the zombies to break through. Fight four.
(You'll miss all the goodies below if you go down the hallway and through the door.)

Go to where they came from.
There's a zombie playing dead lying against a gurney with [BATTERY +15].
In a room at the back is [NOTE_8].

Dr. Leon's Mistake
• Find the report for Dr. Leon's last experiment.

Go through the double doors and kill two zombies feeding.
Proceed through the door.

Explorer
• Explore the backside of the annex.

In the room at the end is [AMMO], [GUN], [MEDICINE] in a cabinet, [MEDICINE] in a fridge, [ENERGY +25], [ENERGY +25], [HEALTH +10], [BATTERY +15], two [BATTERIES] in two lockers.
Three zombies attack as you exit. Plus two more in the side rooms.

Return to the room you started this level in and through the hole in the wall.
[BATTERIES] on a chair.
[NOTE_9] on the gurney.
Try to go into the next room. Turn around, look at the ceiling when it starts raining, down the hall, kill zombie. End hallucination.

Next room, get axe. Pick up [MEDICINE].
"Operating Theater" opposite contains hallucination + zombie playing dead.
Next room down on the left is empty. Right has a zombie on the floor.
Next room down on the left ("Drug Store") is empty again.
Enter "Laboratory" on the right for a scene.

Family Meeting
• Meet with your family.

Automatically read [NOTE_10].

Revenge
• Avenge your mother by killing your father.

The Doctor's Notes
• Collect all the notes.

Exit the room and continue down the hall into the room at the end.

[MEDICINE] in a cabinet on the left.

There are three zombies hidden inside the wall behind the cabinet. You can use the axe to kill them through the wall as demonstrated in this video:

These three zombies may count towards "Zombie Hunter" as well.

Kill the zombie enjoying his meal.

Enter the next room.
[KEY] in the cabinet on the right.
[MATCHES] in the locker further down.
[MEDICINE] on the chair next to the generator.
Go to the opposite corner of the room.
Heal up and use the blue fuel tank to start a fire. Doing so will take up to half a health bar.
Return to the previous room, stick a right, and up the stairs.
Unlock the door, kill a zombie playing dead and down the hole in the floor.

Walk forward for a zombie attack.
Under the stairs ahead is [AMMO], [MEDICINE], and [AMMO] on some chairs.
(I recommend switching to your gun for the rest of the game.)
Upstairs are three zombies, [AMMO] and [AMMO].
(The door under the stairs continues the story, and you'll miss the stuff upstairs.)

Six more zombies (two groups of three) should hear your gunshots and approach.
Down the hallway is more [AMMO].
Downstairs at the back is five more zombies and a [GUN].
Backtrack to the chairs under the stairs and exit.

Three zombies attack after a hallucination, plus two more at the fire.
Continue along the path until you're back indoors again.

Room on the left has [ENERGY +25], [HEALTH +10].
Room on the right contains a zombie.
Room on the right further in has [BATTERY +15].
On the left is a combination padlock. Use code 3749 to enter.

• If this code has changed, check the gurneys in the above three rooms for the correct code.

Up the stairs and return to floor 2.

Exit the cafeteria.

Room ahead has [MEDICINE] on a chair and [BATTERIES] on a chair, and a [LIVE TV].

Down the hall is a zombie QTE and zombie on the floor.
Enter the bathroom on the right.
Inside on of the stalls on the right is a zombie.
The wall behind one of the stalls on the left is broken and leads to the next room.

[MEDICINE] on your immediate right. More [MEDICINE] in the fridge.
[AMMO] on a chair in the back corner. More [AMMO] on another chair at the back.
Switch to your gun for the upcoming sequence.
Exit and continue down the hall until a cutscene.


There's a [GUN] to your immediate left, but I doubt you need it.
Kill everything.

Zombie Hunter
• Kill all the zombies without getting killed.
  (If unlocking properly, this will pop before you even kill every zombie in the courtyard.)

I've been told "Zombie Hunter" unlocks on the easier difficulties as well, so feel free to turn the difficulty down after finishing a Normal playthrough if this achievement fails to unlock.

Survivor
• Complete the game on normal difficulty.

Somewhere between v2.1.13 and v2.1.18 broke the first achievement Welcome Back! - Welcome to Roots of Insanity Remake! which should unlock for simply visiting the main menu.

This should be unlockable by rolling back to v2.1.7:
-app 598440 -depot 598441 -manifest 8359870850359943298

v2.1.7 added a mode where you need to finish the game from start to finish in a single session without saving.
This can be done in about 30 minutes if you skip most of the side rooms and focus only on the objectives. I still recommend picking up the gun in the Annex and you'll need it in the final area and that one is easiest to pick up.

Challenge Complete!
• You won an 'A Way to be Dead' key!

Note: If this mode is removed after the event ends:
v2.1.7: -app 598440 -depot 598441 -manifest 8359870850359943298
v2.1.13: -app 598440 -depot 598441 -manifest 5924836341114103572

The door to the secret room is locked in the current version of the game making it impossible to unlock these achievements.

The secret room is located in Annex-1. Facing the room with the note for "Dr. Leon's Mistake", the door will be on your left. There's only one secret room, and both achievements unlock simultaneously.

Screenshot:
The open door is the room with the note for "Dr. Leon's Mistake", and the closed door on the left is the room you need to enter for the achievements.

Update for v2.1.18:
After downgrading to v2.03, you can no longer load directly into Annex-1 with the autosave created in your v2.1.18 playthrough. Load into the previous level first (Block / Floor2-4) and play to Annex-1 and find the secret room.
I've also been told by multiple people that the secret room may not open on the first attempt. I'm not sure if it's because it's sometimes at another location, or the door is just locked randomly, but if it doesn't open, reload Block / Floor2-4 and try again.

Happy Halloween!
• Find the secret room.

Happy Halloween!
• Find the secret room.

Note: It's possible to unlock the achievements by reverting to v2.0.3 (-app 598440 -depot 598441 -manifest 2230435543471915916).