There are only 6 missable achievements in the game. These are Burn Baby Burn, Retail Therapy, I Chose Not To Read the Sign, Family Fun day, One, Two, Punch and I Made a Thing. These are marked in the guide as missable.

This game does have NG+, and although I did not need it, you dont need to feel too bad if you miss anything! Its relatively quick to backpedal. Most achievements are story based, and require things such as defeating a boss of an area or picking up a necessary collectible. Take your time, and don't worry TOO much. Make sure not to do all story areas (orange areas on the map!) first if you want all achievements in one go! (✿◡‿◡)

Important!
This guide is not written in any suggested order of play, and if I consider something smart to do early, or later, it will be stated for the achievement.
This is the order I got the achievements, but as long as you do not do every story mission first, it should not matter too much. ^o^

Simply defeat the first monster (or any) you encounter in the game.

I recommend using melee weapons as much as possible, seeing as ammo is scarce early in the game.

Do a combo with a melee weapon.

This is simple work. With a melee weapon: Left click, then right click and then both simultaneously - and the achievement should pop. This was the only thing that worked for me, but if it didn't for you then some said just clicking both worked for them!

Craft your first item.

I did in this in the beginning area of the game, with the 9mm ammo. The blueprint is found left of the blue container on the shelf, and the crafting station is next to the storage with the gun. If you miss this one, don't worry! There are lots more recipes and stations throughout the game. Check out this great guide by Rua if you need help with items/blueprints!

Reach Westminister
For finishing the prolouge! Can't miss it (●'◡'●)

Defeat The Grand Stalker

This is the bossfight in the New Lyceum Theatre, found just as you enter the main area of the game.

Find Lady Diana's ID Card

The ID card can be picked up on stage right after finishing the boss fight and watching the little interaction with Lady D.

These achievements are both found in the New Lyceum Theatre, which is the recommended first area of the game. It is right on the corner as you enter Westminster. Below you can see an image of the location. The masks are crossed out because I have completed the area! (^///^)

Go Bowling

Don't get fooled by this being the rarest achievement in the game, because it is very simple to get. I got this after the two achievements above (*/ω＼*)

You simply have to go to the location shown below (there is only one enemy in this area, but it is a little strong, so be careful!), and use F to pick up a bowling ball and hit some pins with it!

Defeat the AFT Maniac

This achievement can be a bit scary if you don't have some decent guns/weapons, so I would recommend making sure you at least have the shotgun before you attempt this! The item that drops from this boss fight is glorious though.

The boss can be found in the ExpenCo Hall, and will spawn after starting the generator. Reminder: You need fuel for the generator to work!

Find Dr Dan Linwood's ID Card

Go through the Royal Hallamshire (The Hospital), and find the id card on the dissection table (not missable to complete the area). It is straight down the corridor when you're standing at the door that requires the card to open.

Find Sir Michael's ID Card

On the body with the Traitor sign, in the room with the King William V crypt and all the equipment.

Defeat King William V

Defeat the bossfight in the St Paul's Cathedral (top left of the map). The room after finding the ID Card (where you need to crouch to get to!).

Survive an Anomalous Storm

I am not entirely sure what the requirements are for one of these happening, but once in a (long) while, when you are outside, an anomalous storm will start. A bunch of enemies will spawn and attack you through the entire duration of the storm, and you have to stay outside the entire time until it ends.

Mine came naturally after exiting the Cathedral, but some players walked in and out of buildings over and over until theirs started. If you can't get one during your play through, I suggest doing that.

I couldn't get a good picture of it for my guide, but in the video below by Arkesh Plays you can see how it looks.

IMPORTANT, THIS IS MISSABLE

Kill An Anomaly With Fire From a Pipe

In the boss fight in the Eastforge Armaments, there will be red pipes you can shoot. These will explode and set the boss on fire, and you need to hit him with the explosion. You do NOT need to kill him with this, just hit him with it.

The pipes, for reference:



Defeat Project Aegis

Defeat the boss in the Eastforge Armaments.

Find Lord Dale's ID Card.

On the floor right in front of a rather gruesome display. Right after entering the Steel Mill.

--

Eastforge is all the way to the top of the map, and you have to go through the High Gardens Entrance to get there.

Defeat the Speaker of the House

Kill the boss in the Houses of Parliament / Palace of Westminster.

Find The Director's ID Card

In the Directors office, go to the left after obeying the directors wishes.

On the left of where we started the game, you need all four ID's you can see outside (main story), to enter. The Palace of Westminster (The Houses of Parliament).

Return to Hanwell

Story, unmissable! ☆*: .｡. o(≧▽≦)o .｡.:*☆

Ignore the Sign.

After the gas puzzle and the tentacle monster in the lab in Hanwell, you will find a dark hallway with a switch and a little note on the right hand side. Under you can see a picture of it. Flip the switch.

Defeat The Doctor

Simply (or not so simply) defeat the final boss of the game.

Complete Beyond Hanwell's Main Content

Finish the game. Congratulations on beating it! ╰(*°▽°*)╯

Thank you so much for reading and using my guide! I'm really glad if it helped you, and if you need any further help, feel free to write in the comments or send me a friend request. Happy to help! Congratulations on your new 100%! ☆*: .｡. o(≧▽≦)o .｡.:*☆