I decided to write this guide to help others finish this game as some translations are so bad they end up hindering your progress. I wrote all of this. You may post it somewhere else with due credit.

This 'horror' game ends up being more funny than scary, but from time to time, jumpscares will annoy the living ghost out of you.

Also, many times, you won't be able to interact with an object (read:progress at all) without interacting with another one prior, which is total bollocks.

This game contains the following:

• Jumpscares
  
• Unnecessarily loud screams and noises
  
• Bad translations

Controls:
WASD to move
F to pay respects interact

Use the urinal.
Lights will go out.
Exit the bathroom.
You will hear footsteps, check the little walking plane atop the lockers in front of you for an achievement.
Interact with the sports team (Rabbits, nonetheless) poster for an achievement.
Go down the corridor as things get trippy.
If you see sparkles around an object, it is probably a journal page. Just collect them as you go (they are VERY, REALLY obvious so I won't mark them here).
Loud scream at the end.
Turn around and stay still, look at the bunny for 15 seconds for an achievement, then walk to where it was.
Try to go up the stairs, interact with the forest for an achievement.
Walk down the stairs, lockpick the door (Skyrim flashbacks, with low budget locks - get it right in one try for an achievement, can be ANY lock).

From the cell you're in, look outside the window to see a spinning bunny for an achievement.
Interact with the door to determine it is locked and be able to look for ways to open it.
From the door look to your left, there's some items in a shelf, take the Horseshoes first for an achievement.
Interact with the door again twice to open it.
Take notice of the hay bales in the little corridor (there's 4) if one is slightly off the wall and close to the center of the corridor, you'll have an easier time getting a couple of achievements, however, you can't get them both on the same run, so it might be necessary to return to the last checkpoint to try again (farming in the barn, get it?).
To open any of the doors in the corridor, interact with their frame (left-side) and you'll enter a mini-game. The gauge is useless though, just mash your spacebar until you open the door.
At the end of the corridor, interact with the metal door to determine it is closed.
Next turn right and interact with the little padlock.
Now, from the padlock, turn behind and you'll see a cell with a dead horse and a fork. Open the cell. Take the fork (you won't be able to take the fork if you haven't inspected both the metal door and the padlock).
Once you have the fork in hand, you will be able to poke the bales (4 times) to find a key. It's mostly a thing of luck, BUT if it just so happens that one of the 4 corridor bales spawns slightly off the wall, that is the right one.
You get one achievement for finding the key on your first try.
You get another achievement for finding the key in less than 3 tries (I did it on the second one after reloading the scene and having another bale spawn a little away from the corridor wall).
Once you find the key, use it on the padlock and enter that cell.
Inside, take the key for the metal door and the bunny will lock you in the cell and start laughing.
You should see some horseshoes on the wall just above the table you picked the key from. Take them and open the door as you did in the very first cell.
/// Loud jumpscare alert ///
Open the metal door and proceed to the next door, which will open and reveal another (wooden) door to the right. Once you open that door you'll see a girl far away. If you try to move or look away you will trigger the jumpscare.

引用自 BrutalComedian：

It can be mentioned that you need to interact with a "Rich club" poster wich is directly in front of you at the beginning of scene 3 for a corresponding achievement.

I finished the game a long time ago so better safe than sorry, thanks for the comment mate!

Walk down the corridor and make your way to the cafeteria (can't get lost in this game).
Once you're in you will have flashbacks of TED your friendly neighbourhood bully.
Approach the cafeteria counter and get your meal, then go back to the entrance and turn left, walking towards the empty table to sit down.
After a brief scene, you'll regain control, walk toward the cafeteria counter again, and a girl will appear to the right.
Ignore her and walk towards the left of the counter, to where the sodas are.
Interact with one of them to get another achievement.
Now walk towards the girl (you guessed it, jumpscare).
You will be back at the first corridor of this scene, just walk towards the rift in space/time (you can't miss it).

Translation is serious business.
Once you regain control, sit on the swing for 15 seconds for two achievements.
Then you will need to set up your campfire.
First you need to find pebbles laying around the camp area, they're fairly easy to find ONCE YOU KNOW WHICH ONES TO LOOK FOR.
They're not in the wall nor should you go looking beyond the walls for pebbles, they're relatively close to the edges of this little area, but it's so dark it's tedious.
Pick 4 pebbles, drop them at the campfire area (highlighted in front of your tent).
Pick 3 more and drop them as well.
Next is brushes. Oh, BRUSHES? I'm sorry I (read: the game) meant BRANCHES.
You should look for piles of 3-4 branches laying around, they are fairly easy to find ONCE YOU KNOW WHICH ONES TO LOOK FOR (again).
Pick a few piles (3 or 4, was so pissed I didn't count) and drop them at the campsite.
Then interact with your tent to get marshmallows or whatever.
Interact with the campfire and you'll be treated to the world's most exciting cooking scene ever.
Interact with your tent to sleep afterwards.

Wake up, follow the girl and walk through the trail across the bridge.
Keep walking and you will end up at a wooden shack.
Once you get in, you will only see a small part of the screen, but go to your right and you will see a pickaxe.
Try to go out the door you came in through and after a few tries with your spacebar, you'll find it's stuck.
Quickly go grab the pickaxe after this to get an achievement.
Once you have the pickaxe, interact with the door.
Not much else to do, walk to the bathroom and into the small room to the left of it.
You will see shadows scurrying about through the window, if you go back to the first room, the pickaxe is gone.
In the room where you saw the shadows, interact with the floor to reveal a hatch, and interact with it a couple more times to enter it.
Bunny will lock you in, but you can open the door behind you and keep walking.
Climb the vines.
Keep walking and interact with the girl until you can go through the door.

Back at the school corridor, you'll see Amy (the red sweater girl). Walk towards her.
As you reach her, the corridor walls will move.
Turn around and walk towards Bunny, keep chasing after him until you reach the auditorium.
Take a seat and watch the scene.
Walk outside and towards yourself. You will end up in a bedroom.
At this point, before you do anything, you can exit to the Main Menu change the language to Turkish and resume your game to turn on the TV and get an achievement.
Once you change the language, choose the 2nd option in the main menu OYUN'A DEVAM (this one is resume game), then EVET.
Get out of the cupboard and turn on the TV (the scene is different in English and you don't get the achievement).
Once that is done, press ESC, choose ANA MENÜ'YE CIK (last option), then EVET to go back to the main menu.
Choose OYUN AYARLARI (options menu) and switch back to English.
Resume the game.
Try to open the night-stands (bed-side tables) and they will say you need a buckle.
Only god knows what that word is intended to be. You can open all drawers and most closet doors, but there's nothing.
Atop the drawers, a little left to the picture, mouse over the things to pick up what I assume is a hairpin (the buckle? whatever).
Proceed to interact with the night-stands and open them.
The first one you open has your mom's diary. The second one has a gun.
Enjoy some fun time with dad learning to shoot.
In the little shooting game with Bunny, if you shoot 3 or 4 targets out of the total, you'll get an achievement. Just as a note, 4 is the max you can get.
You can't get both in one run, so you will have to replay the scene to get both (you restart at the bedroom).
When aiming for the 3 hits achievement, shoot 3 targets and deliberately miss one shot.
Watch the rest of the scene and interact with the closet to hide.

As the scene starts, walk to the end of the corridor and interact with the door directly left of the double doors at the end of the corridor (the ones with the 4:20 sign on top of them) as quickly as you can to get an achievement.
You can restart the scene and explore the classrooms if you want to (I didn't).
Wait inside the classroom and enjoy the world's greatest fishing trip with dad (dem rowing skills). Press F when indicated.
Don't worry about the fishing mini-game, it's meant to be near impossible.
Mash your spacebar when indicated.
When you're back in the classroom, grab the floating page (Got the 10 page achievement here).
When everything is Bunny (you'll know), go to the empty seat in the back and grab the page.
After the most exciting sequence ever, press W, Bunny will startle you when you reach the door.

A(n actually) cool cutscene plays out, then you're in the bathroom. Prom night.
Some journal pages pop up in sequence (Got the 15 page achievement here).
Show time.
Press W until you find William. Press E to knock him. You get an achievement.
Restart from last checkpoint and choose the other option to get another achievement.
Shoot everything else that shows up to get the final 2 achievements.

There's a post-credits scene. Watch it if you want to (I'll admit I did).

Special thanks to MalcavianChild for his fantastic guides on achievements, which you can visit here.

Final thoughts:
This game would certainly cause a ruckus in today's special snowflake world.
Nothing makes sense plot-wise, it is badly written, translated and obviously low budget.
Still the message is clear:
don't do drugs and guns (or at least not at the same time, and certainly not at school).

Thanks.