There are 6 achievements in total, you can only get one of 2 endings in a single playthrough along with the rest of the following achievements. So a second playthrough is needed to get the other ending if you are a completionist.



Unmissable one, will unlocked when you successfully delivered the last package.

There are 11 knocks in total, should be more than enough to get both achievements in a single playthrough.

Ending 1 : You read all 3 letters, you will escape.
Ending 2 : You didn't read all 3 letters or only read some of them, you will die.


There are 36 collectable cans in total (just for fun) around the first/ground floor.

I have referred a comprehensive guide by another contributor to find all of the cans.
https://gtm.steamproxy.vip/sharedfiles/filedetails/?id=2508857379

• Deliver a package to a drunk man in apartment 206.
  
• You will be able to knock 3 times, you are free to choose whether to knock or use the intercom first.
  
• You will get a bottle of water. This can be picked up later to find a dog's letter, the dog will be somewhere in the mini playground.

• Deliver a package to a lady in apartment 502.
  
• You will get a cat food. This can be used to feed a stray cat sitting on top of a dumpster and another letter can be found inside the dumpster.

• Deliver a package to a man in a sweater in apartment 401.
  
• Use the elevator to the 5th floor and go downstairs to the 4th floor to deliver the package.
  
• At this point you will be able to unlock the Knock Knock or Intercom achievement, and you can start using a different way for the next deliveries.
  
• You will have to go back and forth to a Priest's apartment in 105 for about three times.

• Deliver a package to a lady in apartment 305.
  
• Take the package and set up the bed frame at the corner of the room with a red arrow pointing at it.
  
• Check the room next to you before you leave.

• Deliver a package to an old lady in apartment 202.
  
• Find the baby at apartment 403.
  
• The apartment will be full of photos of a mysterious fridge.
  
• Go to the balcony to find a pot and knock it over. Later you can pick it up to find a mailbox key.
  
• Check the bathroom and toilet.
  
• Go into the room on your right, open the cupboard and leave.
  
• You can refer to this simplified apartment directory[imgur.com] to find your way to deliver the packages. Easiest route would be : 105, 202, 502, 401, 206, 305.
  
• Drop off the baby at apartment 202 and you will be able to unlock the Package Delivery achievement.

• Pick up the mailbox key from the fallen pot all the way around the block through the street where the van is parked.
  
• If you are going for Ending 1, open mailbox 404 and read the letter Otherwise, you can just leave it.
  
• Get a mysterious package from the van and deliver it to apartment 404.
  
• You will be able to knock or use the intercom here for about 4 more times.
  
• There is a welfare document you can read on the table in the kitchen.
  
  Ending 1 :
  
• You will find a fridge in the middle of the room, leave the apartment and you will see all of the previous residents lifelessly staring into the apartment windows.
  
• Click on the door to advance the story.
  
  Ending 2 :
  
• You will find a fridge in the middle of the room and dead bodies of the previous residents all over the apartment.
  
• You will be playing as the landlord and your job is to go to apartment 404.
  
• Take the flashlight and leave the apartment.

Thanks for reading!
Let me know if there is any mistake or anything I have left out.