A Real Class Act
Get 5 kills using Manhacks only.
Easy to get by killing 5 civilians in Firing Range.


Ten Sterilize Credits
Kill 10 rebels.


Twenty Sterilize Credits
Kill 20 rebels.


Thirty Sterilize Credits
Kill 30 rebels.


Forty Sterilize Credits
Kill 40 rebels.


Fifty Sterilize Credits
Kill 50 rebels.


Eviction Notice
Evict 20 Vortigaunts from Pillar 10. And from the realm of the living.


Simply can't be missed as progress towards chapters. Civilians are also count for Sterilize Credits, so just start Firing Range and keep killing them until it unlocks.

Cremator
Ignite 20 Zombies using flares.
Pick up a flare and throw it at a zombie, simple as that. Flares are located in the tunnels from the chapter, Low.

These are three collectible achievements:
Beaches Babes and Waves
Find and wobble 7 Hula dolls.


Garbage Poet
Find all of the poem pieces.


Next Generation
Find all of the Lambda Generation tags.


You can replay chapters if you missed them.

Sucker's Luck
Wake up stranded in City 10.
Story related, can't be missed.

Lambda Generation (1/7):
After killing the rebel, turn around, next to two crates.


Hula doll (1/7):
Once you killed a poison zombie, a hula doll is on a shelf.


Picked up that can
Pick up a can.
Press E to pick up a can...


Threw it in the trashcan
Throw it in a trashcan.
...to throw it by pressing Mouse left click.


Hula doll (2/7):
On a side table near a fireplace.


Lambda Generation (2/7):
As soon as you see a loose door. Simply through to find a tag.


Hula doll (3/7):
On the hood of the yellow car in the mechanic shack.


Lambda Generation (3/7):
Between the two transformers, next to the electric station.


Poem (1/10):
Once you solved the electric station and the strider's head exploded, a poem is left to the door.

Subtle Cop
Sneak through the rebel encampment.
You have to stealth through until reach the turret room. Pull off barrels, move up wooden circle and reach the building. Quick save is your friend as a rebel can't be seen.

Deadly Exploit
Turn the turrets back on the rebels.
Story related, can't be missed.

Lambda Generation (4/7):
Once you reprogramming the turrets, a tag behind the staircase, next to the turret.


Hula doll (4/7):
On a shelf, behind a turret.


Poem (2/10):
In the room labeled "First aid", is the next poem.

Lambda Generation (5/7):
On the right side of the tenant hallways.


Hula doll (5/7):
On a table next to a lever.


Poem (3/10):
In the supply room where a rebel shotgunner is killed.


Kindergarten Cop
Return the doll.
After reaching the jail cells, turn right and enter the bedroom.

A doll is located on the floor below.

Once you picked a doll, bring it back to the bedroom.

Note: Do not throw a grenade into the machine, this will lock an achievement.

(Very) Dead Tenant
Find the dead rebel leader.
Story related, can't be missed.

Still Alive
Survive the betrayal.
Story related, can't be missed.

Vague Voices
Did you hear that?
Simply can't be missed as through the tunnels. You'll hear a monster whisper threatening things, hearing 3 lines to get an achievement.

Lambda Generation (6/7):
Underneath the stairs, next to HEV Suit Charger.


More Gun
Find a prototype AR2.
Story related, can't be missed.

Hula doll (6/7):
In the room, next to two crates...


I know the pieces fit
Find the reference.
...and behind it.


Poem (4/10):
In the room with an AR2 ammo crate.


Plosive Expletive
Survive the grenade encounter.
Story related, can't be missed.


Hula doll (7/7):
Where a stalker take the elevator up to the next landing, a hula doll is on a shelf.


Poem (5/10):
Near an electrical box and AR2 ammo crate.


Lambda Generation (7/7):
Once your NVG is back online, go straight to the end of the hall to find a tag.


Baby Sittin' Job
Protect the Stalker in the tunnels.
Story related, can't be missed. If a Stalker is dead, restart last checkpoint and try again.

Poem (6/10):
Once you reach the red carpet, a poem is left, on the wall.


Solo
Survive the tunnels.
Story related, can't be missed.

Poem (7/10):
Once you complete the laser puzzle, a poem is in the room, near the stalker.


OUTBREAK OUTBREAK
Experience your first CFLU fever.
Story related, can't be missed.

Poem (8/10):
After the possessed Hunter fight, a poem is in the room beside a vaccination point.


Hunter Killer
Kill the possessed Hunter.
Story related, can't be missed.

Poem (9/10):
Once you killed the possessed Hunter, a poem is where you came.


Poem (10/10):
After two purple vortigaunts killed, turn around at the staircase.


On Ice
Destroy the Quantinode core.
Story related, can't be missed. To get kill the final vortigaunt, you have to use a shotgun to blow him off. As soon as the shotgun eat out of ammo, take the pulse rifle to finish him off.

Bullet Hangover
Die 100 times.
Self-explanatory. Easy way is to use quick save while below 40 health and keep load. You will get it under ~3 minutes.

Beat Cop
Complete the game on Normal mode or higher.
Simply complete the game on Normal or higher. Easy, right?

Bad Cop
Beat the game on Bad Cop difficulty.
If you still suck at this difficulty, type "sv_cheats 1; god; sv_cheats 0" into the console without quotes and go fresh.

If you'd like to complete 100% achievements from the sequel game, check out my guide:
https://steamproxy.net/sharedfiles/filedetails/?id=2852616572