There are a total of 16 achievements in the game.
Before you begin, there are some things to take into account. A lot of progress towards the achievements will be unlocked naturally just by playing the game, however, if you vary your combat style you will lessen the grinding at the other end. Use finishers and stomps as part of your regular combat techniques, because farming these all at once will be very boring.
Certain achievements will benefit from specific aim assist settings, which will make obtaining them easier.
In challenges even if you die achievement progression for kills will count, you will not lose progress if you die.

Cowboy

Complete the Weeper’s Challenge with a revolver.
Stock up on revolver ammo from other challenge runs and the story mode. You can use your reserves from your storage box, play the ‘Desperate Weepers’ challenge on easy mode and only use up the Revolver.

Don’t Cry

Kill 100 Weepers
Use the same tactic with saving ammo reserves on the ‘Desperate Weepers’ Challenge mode. As only Weepers spawn on this mode you will easily get enough kills.

They Used To Be People

Complete the abandoned hanger without killing any enemies
This one is easier than it seems, I have included a video run to show how I can consistently get the achievement. There are some points to note: Do not pick up the knife at the beginning, because if you are grabbed Jodi will use the knife and kill the enemy. Make sure to grab all the items I do; they will make your run easier. When approaching the Weeper make sure you are on full health or at least not injured, as you need to be moving at full speed. The revive spots I use are to despawn enemies, and if you die you can respawn with an easier run ahead. Do not get the revive spot at the bottom of the building site until you have alerted the last Weeper and died. You need this Weeper to despawn.

Easy Peasy

Do not use the Zombie Brain Smasher to complete the Centralized Control Area.
Select easy mode for the Centralized Control Area challenge and use any weapon to finish the challenge with the exception of the ‘Zombie Brain Smasher’. This is easy and should not cause problems, you will likely get it by accident. The Predator can easily be downed with two mines.
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Don’t Touch Me

Clear the Test Grounds without taking damage
Select easy mode for the ‘Test Grounds’ challenge and go through the far-left door. Run around the picking up all the weapons, once you are armed depending on your preference there are different tactics available. I set up at the top of the stairs to the left of the ‘shop door’, this gives you plenty of time and distance to kill enemies before they get to you. Another method is to kite around the lower section, keeping your back to the wall and constantly moving. As long as you keep moving you should not get hit.

One Woman Army

Complete the Restaurant Challenge without using defensive devices
It is important to note that all three generators do not need to be used or even survive. I used generator B, as I found it the easiest to defend, but try them out and see what you think is the most defensible. The best way to get this consistently and without too much trouble is to stock pile ammo and weapons from the story and other challenge modes. I personally used the Sub-machine gun and the Assault rifle, but use what ever weapons you feel comfortable with. Be careful with the hazmat zombies, as if their gas tank explodes nearby it will do a lot of damage.

Solid As A Rock

Complete the Restaurant Challenge without firing guns or using melee weapons
Similar to the other achievement for the Restaurant Challenge, use stockpiled defensive items and places the zappers and blades surrounding generator B, I used around 20 to get this done easily. Remember to take some healing items as a back up. Do not take or pick up any knives, as if you get grabbed Jodi will uses the item. Keep an eye on the lights of the defensive items and when it gets low, swap it out. Take some with you to the extraction site and places them at the bottom of the stairwell/ building under construction, as there is a Weeper that will be blocking your path. Once she agros, run back to the zappers.

Charge Ahead

Complete Story Mode without loading progress
This should only be attempted when you are comfortable with the entire story section of the game and playing on easy. You must complete the story in one sitting without dying. There are three areas that will cause players trouble, the Devourer chase, the fan in the tunnels, the stealth section, as these are the most likely areas players will die.
The game has since been updated and a lot of the tactics are obsolete.
Dropping items at the shower no longer works. I advise playing practicing the run and playing on easy mode as you will have more stamina and thus be able to run further. You will find a stamina drink in the room you drop down into, use this when your stamina is almost depleted.
The stealth section has been made much easier, you will have a bow and arrows, so you are far less defenseless.
The fan can be avoided by quickly pressing the button and dashing through the door before it closes. When you get to the fan, press the button so the door to the left of the switch is open, position yourself closer to the door and press to close again, while dodging through it. You will then be able to open the next door without going through the fan.
Thankfully, you can stack the odds in your favor. For the Devourer chase, drop two knives, or even guns and ammo before you activate the cutscene.
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If you drop them in this area, you have a few seconds to pick them up before running. You can drop enough ammo to kill the Devourer, but I recommend running. Once you drop throw the knives to open the wooded door to create a short cut, no zombies will spawn, and the Devourer will not pursue you.
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There is a second door you can also open with knives to make this area even shorter.
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Miss Popular

Get grabbed by zombies 300 times
While playing the Story and Challenge for the other achievements you will likely get this just by playing. When a zombie gets close enough to Jodi, it will grab her and bite her on the neck, do this 300 times for the achievement.

Rough Economy

Kill 3 or more zombies with one bullet
I recommend the Pistol or Revolver for this achievement, as far as I know the Shotgun will not count. There are several areas where you can line zombie up including, the Combat room on A5 near the end of the game. If you wait for the zombies to break the wall that is to the left of the ‘Shop Door’ go though and down to the right as you enter.
The enemies will file in, and you should be able to line up three eventually. In the Centralized Control Area challenge, you can use the doors at the sides that the enemies spawn from as a funnel, this will help you line them up. On challenge maps you can also upgrade the Pistol and Revolver for further damage.
There are many other areas, but these two are consistent for grouping large numbers of zombies.

Master of Headshots

Headshot attack 2,000 times
If you want to make this really easy put aim assist to max, it will auto aim for enemy heads. As it is a large number farm this while you go for other achievements and unlock clothing. You will get a lot of head shots just for playing the game.

Blood Dancer

Kill 1,000 zombies
Pair this with the above achievement, if you play the game there is no way I can think of that you can miss this.

The Pitcher

Throw a weapon to kill a zombie from 10 meters away
I would recommend turning the auto aim off for this one, as you will need to aim high to arc your throw properly. If auto aim if on you will not get the distance. The Centralized Control Area challenge map is the best for this achievement, as it gives you the biggest area with respawning enemies. Kill all but the last Squirter and lead it so it comes straight at you, line up the throw and aim high. It may take several tries to get the distance and throw technique.

Pedal to the Mental

Stomped 500 zombies to death
Time for the Shotgun to shine! Load up on shotgun shells from your stash and go hunting some zombie kneecaps. This can be done on any mode, but I found spawns on Story Mode to be easier to farm. Shoot the zombies at the kneecaps to cause them to fall, stomp on their heads to finish them off(RB-Right Bumper). This will take some time, so do this regularly to slowly build the number up while going for other achievements.

Sharp Shooter

Destroy 100 venom chunks spewed by the Squirters
This one is tricky, but there is a method to make it much easier. You will need to turn aim assist and auto aim off for this one. I recommend using the assault rifle or submachine gun for this. Load up the Centralized Control Area challenge, and clear until you have one Squirter left. Position yourself on the other side of the wooden table to the Squirter, bait it until it shots the venom at you. You want to move backwards and to the left as it wretches before spitting. This makes it spit the chunk at a nice arc that you can easily shoot it in midair. You want to aim slightly to the left of the Squirters forehead, and fire short-controlled bursts. It may take some time but practice the timing and you will get it. Check the video for an example of this movement.

Executer

Execute 1,000 zombies
This is done with a melee weapon, either the knife or the axe. You need to stagger an enemy (zombies are best) and press the (LT-Left Trigger) to perform a finishing move. You can trigger a stagger by using the pistol and shooting zombies in the chest, quickly switch to melee to finish them off. You can also trigger a finisher when a zombie is getting up off the ground, once it is halfway through the animation press (LT) to execute them.

Buy 1 Get 1 Free

Kill 2 zombies 100 times with one bullet
You will likely get progress for this just by playing the game, with the exception of the Shotgun all other firearms will go through multiple zombies’ heads. This can easily be achieved in the sections mentioned for the ‘Rough Economy’ achievement. Using full aim assist and funneling zombies into a tight corridor will make this much easier. I recommend both the Pistol and Revolver for this, as it will go through heads easily. In challenge modes you can upgrade your weapon of choice to make them more powerful and boost you chances of a multi kill.
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Super Star

Dress up 1,000 times
Once you collect clothing items from the Story and Challenge modes you can use mirrors or even Jodi’s inventory to try on new clothing. Experiment making new looks and outfits for Jodi and you will soon unlock this. All you need to do is equip clothing items 1,000 times.
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