These four achievements are very simple to get, the first two I recommend to unlock them before approaching seriously the story campaign, because they lead to an ending:

• Stressed Out: During the game you have to pay attention to your level of fatigue or stress, totally ignore it and you will get this ending.
  This ending is not considered canonical, so it doesn't erase the savegame.
  
  
  
• You Died: During the game you have to pay attention to the level of discontent in the village, take it to the max. To speed up the process you can hurt and kill customers with your knife, so you'll get this "fiery" ending.
  UPDATE: Even maxing out your discontent by getting caught trying to break into the vendor's chest will trigger this ending.
  This ending is not considered canonical, so it doesn't erase the savegame.
  
  
  
• Rat Slayer: UPDATE: Choose the option to exterminate rats during the Rat Slayer event.
  
  OLD:During the game at the beginning of the working day, random events can happen, one of which involves you while walking in the woods to recover healing herbs for your pantry. Finding a beautiful bucolic place, is given the choice to spend the day there, do it and you will get this.
  Subtle irony in this achievement despite the name, if you haven't noticed it even before the bubonic plague arrives, the village is invaded by rats, so taking a break is understood as an alliance with rodents. However even playing normally, this is the best choice, because it will cure all your stress.
  
  
  
• Greed: At the tavern you bet on the dice game, if you win four times in a row, you get this simple achievement; there is no trick to get it, is all RNG.
  
  
• One More Day: Reach the 11th day.

Small anecdote: You will have noticed how intelligently the 5 disturbing inhabitants were entrusted with a right vice, depending on the context of the plot, but Envy and Greed ?
It could be argued that the character who plays the role of Lust may also be that of Greed, but this is not the case. In fact, Greed is the main character, based on the choices made during random events. The latest update that adds achievement "Greed" again, reconfirm this theory.
While for Envy there is no real role, unless you consider any consequences given by some particular choices always made in the events, concerning the real healer or the viscount's son.

However to get these achievements, just be kind, charitable and interested in the illness of the characters, when they show up in the workshop.
So always choose the best answer and never drive away the aforementioned inhabitants in a bad way.

• Gluttony: Just cure the drunkard's hangover, done this, he will thank you but it will continue to bother you in the future!
  
  
  
• Wrath: Take care of the gangrene of the mayor's son, after two days the mayor will pass to thank you for saving his son's life.
  
  
  
• Pride: When the blacksmith finally agrees to be cured, after two days, he too will pass to thank you.
  UPDATE: You have to pass the eye surgery mini-game.
  
  
• Sloth: The priest will appear on several occasions and each time you must hearten him and invigorate his faith. When finally you give him a nice herbal tea and his depression magically passes, he will thank you.
  
  
  
• Lust: This is the longest to obtain, because the beggar shows up several times in the workshop. You will always have to treat her lovingly, accept her demands, and give him some charity.
  UPDATE: Obtaining this achievement is now much easier, as the last part has been completely removed.
  
  OLD: On the tenth day she will show up with strange symptoms, you always treat her every time she shows up. It seems that some combinations of choices don't unlock it, but if you choose the first two times to prepare a herbal tea, then cure conjunctivitis, pustoles and lastly apply bloodsuckers; then you will get it. The important thing is to always choose to cure her.
  
  Other working method by aquatorrent:
  
  Here are the choice for curing the beggar on the tenth day: I have terrible sore throat > Prepare an infusion from herbs and onion (Cold) I'm feeling sick, so sick > Pump the stomach and perform bloodletting (Poisoning) My eyelids are sticking together, I can't see anything! > Make an infusion from herbs and put a compress on eyes (Eye imflammation) How could I not notice that sore bump? > Open the abscess and apply a poultice (Tumor) I still don't feel good, healer > Perform bloodletting

I noticed that if these 5 characters are treated, they become less harassing; the mayor and the blacksmith disturb much less, the visits of the priest become rare and last less, the beggar steals less but the drunkard ... you will hate him, pure hatred!

These achievements all lead to an ending and can be achieved during the eleventh day, with the exception of "Saving Your Own Skin".

• One of 25kk:
  UPDATE: At the beginning of the eleventh day, don't wear the mask when a plague infected patient arrives and wait.
  
  ATTENTION: This ending is considered canonical, so it erase the savegame.
  
  OLD: During the eleventh day, treat all your patients without ever wearing the monat mask. At the end of the day, you'll get this bad ending.
  
  
  
• Saving Your Own Skin: You get this at the end of the tenth day.
  I'm not sure if treating the 4 special inhabitants (excluding the mayor, why fail his quest, with the UPDATE now you get a different ending) well or badly in a different way, can serve to unlock this ending but this is definitely a way to get it.
  UPDATE: Instead of leaving to ask the viscount for information, you decide to stay in the village, simple as that.
  This ending also results from not confronting the bandits.
  
  ATTENTION: This ending is considered canonical, so it erase the savegame.
  
  OLD: Play normally, taking care to keep stress and discontent under control but when the 5 special inhabitants show up, treat them badly and send them away, refuse to cure only them.
  You practically do the opposite of what it would take to get their personal achievements.
  So don't cure the drunkard, the mayor's son and the blacksmith, make the priest lose totally faith and treat the beggar badly and don't do charity.
  
  OLD: Other working method by aquatorrent:
  
  I got "Saving Your Own Skin" achievement by not treating the beggar. I did help the blacksmith to cure his eye and didn't treat the others. I think you just have to refuse to treat the beggar on the tenth day and answer wrongly.[/strike]
  
  
• Savior: Simply win, coming out alive and victorious from the eleventh day, you have to remember to always wear the monat mask when you can.
  UPDATE: The refill mechanism has been completely removed and replaced with a visual effect of immediate and permanent fogging (little discomfort), the mask can still be removed and worn, so be careful.
  
  ATTENTION: This ending is considered canonical, so it erase the savegame.
  
  OLD: After taking off the mask, it will have to recharge, wear it immediately after a few seconds when it has recharged. So try to stay as little as possible without protection otherwise you will die and you will have the bad ending.

Achievements eliminated and no longer existing and obtainable.

• Greed (OLD VERSION): Hidden achievement, unlocked by earning 10,000 coins.
  
  
  
• Early Bird: Obtainable by buying and starting the game when it was in E.A. , eliminated at the behest of the community.
  
  
• Dead Inside: Before facing the eleventh day, make sure you don't have any discontent value and stress, if you have it, bring it back to zero.
  During the eleventh day, you don't have to do anything, you just have to wait for the patients to die inside the workshop because of the plague. To avoid any problems, avoid speeding up the process by stabbing them, although it is tedious to wait without having to do anything, you will just have to wait a few minutes and the achievement will be yours when the bar of discontent has reached its maximum.
  This ending is not considered canonical, so it doesn't erase the savegame.
  UPDATE: replaced by the achievement One more day.

Achievements that can be obtained after the latest update.

• In the Moss: When the event to collect leeches from the pond appears, choose the option to spend the day resting on the moss.
  
  
• Druck: There are 5 bottles that can be drunk, 2 in the Tavern and 3 in the Store, click on them until they are completely empty.
  SECRET ATTENTION: Drinking the bottles will open a new line of conversation with the drunkard in the tavern, who will give us a strange flask. Both answers will grant us the flask, but the second one will increase the negative reputation.
  
  
• I Hate Jean: Long as an achievement, but simple: first you have to retrieve the strange flask from the drunkard, then when the event comes where the protagonist wants to try to drink it, accept and once in the warehouse, try to get a very good result with the minigame.
  
  
• Graham Young: Long as an achievement, but simple: first you have to retrieve the strange flask from the drunkard, when the event comes where the protagonist wants to try to drink the flask, choose the option not to do so, because it will then have to be offered to sick viscount at end of game.
  
  
• Chicken!: Long as an achievement, but simple: avoid getting the lucky coin, when you are attacked by bandits, decide to face them and go to your chicken fate.
  
  
• War Never Changes: Long as an achievement, but simple: let the mayor's son die of gangrene, and when the event of the real doctor's arrival appears, choose the option to tell a lie. At the end of the game, the guards will arrest you.
  
  
• What's in the Box?!: Long as an achievement, but simple: Before starting a run, enable Samhain mode in the addons. Then talk to the saleswoman and ask her why she is bored, then you can collect the 6 bundles of berries. After collecting them, be careful because this action can only be done once, so be sure to wait until you have the picklock. Talk to the saleswoman again, she will leave the shop and you can rob freely.
  P.S. Avoid the arrow is better.
  
  Thanks to Haiken for his research on this solution.
  
  
• Die Hard: Finish the game with the good ending in Hard mode, "One life" activated and no tips.