Before we get started, just a few points to make things clear :

• Spoilers ahead !!! This should not come as a surprise, but I will make no effort to not spoil the story, so I recommend you beat the game before reading this guide.
  
• Campaign achievements are organised by the chapters they are completed in, in chronological order. Achievements that are unlocked over several chapters are grouped together in the last category. Speedrun mode achievements are found in a separate section after that.
  
• Note that all campaign achievements can be done on an already existing savefile, regardless of your previous decisions, so no need to reset ! Replay and finish a chapter and your choices will be overwritten.
  
• If you have anything to contribute to the guide, please let me know in the comments !
  

Prism key
Just at the start of Chapter 1, after you kill the two gunmen, come back to search the first one's corpse. You will get the Prism Key.


Don't hang up!
In Chapter 1, during the first phase, repeatedly hang up when the psychiatrist calls you, until all he says is "..." (five times) then ansswer with "Hello?". You will then get the achievement.

Feline Persuasion
This one can hardly be missed, and refers to a vital feature added post-release, that of petting a cat.
In the first chapter, in the first actual room, there is a cat in the office in the top left. Once you have killed all the bad guys, simply go see the cat and interact with it five times, after which it will walk off and you will have unlocked the achievement.


Master key
In Chapter 2, on the last floor, you must kill Josh Rose. Don't approach him or you'll trigger the dialogue and he will jump off ! You have to toss an item at him, you can do it from a safe distance. If you fail, just restart. Once you've succeeded, search his corpse and voilà !


What a bad idea
In Chapter 2, when Josh rose is dead, simply jump off the balcony yourself.



Prototype key
This one depends on whether you took your medicine before entering the prison. If you did, you will need to avoid and spare all the cops, but if you didn't, you will have to kill them all. Basically, just do what the phonecall at the beginning tells you to, and when you get home, you will find an obvious suitcase with the Prototype key in it.

Party Animal
At the beginning of Chapter 5, instead of visiting your psychiatrist, you will go inside V's limousine. When he asks you for your sword to do a line of drug, accept ; you will not get it back until you reach the elevator at the beginning of the level, which is when you will get this achievement.


No love for robots
In Chapter 5, go to the second floor (A Space Uncertainty), and do not kill the robot ! Just go get the keycard, and listen to his entire speech on your way back to get the achievement.


Coffin Head
In Chapter 5, after having retrieved the keycard on the third floor (Quiet Hills), you will come across Coffin Head on your way back -it's actually kinda scary. But he's just cardboard, so slash him in half to get the achievement. Also, play Silent Hill 2.


Beatdown
In Chapter 5, you must "win" the battle against V in Chapter 5... although it ends the exact same way as when you "lose", with Snow showing up. Here is a video on how to do it (read the description !).


Phoenix key
In Chapter 6, you will reach a part where there is a burglar in the top left room. Don't open the door or he will stop to take a defensive stance ! Just wait until he is done scavenging the purse, which will take almost all of the level's timer (better kill all the enemies in the meantime). When he is done, search the bag and you will get the key.


The End
At the end of the gameplay phase in Chapter 7, choose to die. This doesn't have any lasting effect on your savefile, don't worry.


The Dragon's tape
Simply beat Chapter 8 to earn this achievement.



Savant key
Did you know you can skip almost all of Chapter 9 ? Watch for sensors on the ceiling, these will trigger the screen and traps when you pass under them, but they won't detect you if you roll past ! You must not be seen by the ones above the equipment Leon blows up to get this key.


Funny Prank
In Chapter 10, kill yourself in an elevator, which can be done by throwing a molotov cocktail at your feet. Make sure you do it before the elevator stops or your inventory will be reset !


To be continued
Just beat the main game (this means the Mask of Life route).


Refused medication
First, you must disobey and listen to DJ Electrohead in Chapter 3, he will tell you about a drug he took. Mention it to the psychiatrist at the beginning of Chapter 4, and keep asking him about it until you get the option to refuse your medicine. Make sure you keep refusing until he asks you to leave.
Note : Not taking medication makes you suffer from withdrawal during Chapter 4. Your target's dossier will change, and when receiving the phonecall, the Mask of Death will speak to you !


Forbidden Ultimate Danger Tempest-Eyed MAJORDOMO Imperial Barrage Crab, Evixion
First, tell the receptionist in Chapter 2 that you are cosplaying as Shinju from the Sakura anime, a card game anime. Make sure she lives at the end of the chapter ! You will need to talk to her again at the beginning of Chapter 10 : you must then ask her to let you go, tell her you can show her your trap card, and accept her challenge. Anything you say in that dialogue from there will get you the achievement.


Secret hunter
This achievement is unlocked by finding all five secret keys (see chapter 1, 2, 3, 6 and 9).
Note : Each key unlocks a new sword in Chapter 12, the government lab. You must search the psychiatrist's body in chapter 11 to access it.


Psychotherapy
After extensive trial and error testing, I believe I have all the conditions for this figured out, but do let me know if it does not work for you. First, make sure you have done the following :

• Hang up five times during the beginning of Chapter 1, until all the psychiatrist says is "..." and answer with "Hello?" (same as Don't Hang Up achievement)
  
• Pick the red dialogue options with the psychiatrist in both Chapter 2 and 3 (urge him for the medicine)
  
• Refuse your medicine in Chapter 4 (requires to talk to DJ Electrohead in Chapter 3, see Refused Medication achievement above for details)
  
• Say "♥♥♥♥ you" to the psychiatrist during Chapter 7 (you can just mash Skip during the entire dialogue, it's a red option at the end)

Once that is done, go talk to the psychatrist in Chapter 11. I'll let you see what happens for yourself :)

This section refers to the achievements unlockable from the speedrun mode accessible from the main menu. Please note : you do not have to complete a speedrun session in a single sitting ! You are free to quit and resume after any chapter. Don't make the same mistake as me and beat hard mode in one go ! My poor head hurt that day…

Hardmode
This one is straightforward enough : in the speedrun section, there is an option to enable hard mode. All you need to do is complete it… There is not much advice I can give you for that one, as it is not this guide's objective. But let me warn you : it certainly makes the game MUCH harder !

Gold Medal
This one requires you to beat speedrun mode with a global score amounting to a gold medal. Well, platinum works too, but if you can already get that you don't need to read this…
In more details : at the end of each chapter, you are awarded a medal depending on your time compared to the chapter's target time. Deaths do not account into this, but obtaining a gold time without dying once will award you a platinum medal ! The final medal you are awarded for your run is an average of all medals, rounded down, meaning that to get a gold medal you will either need to have scored gold in every chapter, or compensate any silver with at least one platinum, and any bronze with two.

Note : hard mode doubles the target time of every chapter, so if for some reason you do not struggle with it too much, I suppose that could make getting gold easier for you ! Of course it would make platinum medals much much harder to get…

If you wish to check the medal requirements in more details, head to the wiki here[katana-zero.fandom.com].

Shoutout to Breversa for helping me correct the Prototype key achievement.

Thank you to the people complaining about me not updating the few missing update achievements, that gave me the motivation to actually bother with it x)

Thank you for reading, and a huge thank you to everyone involved in the making of this incredible game ! Please consider buying the soundtrack on Bandcamp to support the artists :D

The game has a large free DLC in the works, which surely will add plenty of new achievements. When that releases, I will try to update this guy as soon as I can !