As of Jan 2, 2016, all achievements have been discovered. We've offered solutions to the best of our ability. If any of the information is either vague or inaccurate, please leave feedback in the comments. Thanks! -- Hugo & pgann

Jan 22 -- we made a quick update to include the EX DLC achievement.

Jan 2, 2021 -- We revisited the guide five years later, correlating the various changes the devs made (mostly during 2016 and some during 2017), and using feedback from users in the comments section to update descriptions, remove old achievements, add new achievements, make other clarifications as to how to obtain certain achievements. For significant changes, credit was given to community members for help.

A New Cyberpunk Adventure
Completed the Prologue

Blackout
Completed Chapter 1

Tears in Rain
Completed Chapter 2

No Turning Back
Completed Chapter 5

The Pale Rider
Completed Media Arc

Cloak and Dagger
Completed Flower Arc
Also sometimes referred to as the Vincent Arc, as you are helping Vincent Mensah.

Iron ROM
Played through the game in a single session. Never used a load, or continue.
Note: it's important to know where the fail states (game overs) potentially exist. One of them is the achievement for knocking on doors of Hayden's neighbors too many times. Another two are the key events at the end of chapter 6. Make it to any of the endings 1-4 and without stopping or failing and this achievement will be yours.

Put The Thing in the Doohickey
Puzzled your first puzzle!

Audiophile
You listened to the entire soundtrack!
Should unlock automatically if you play through to the end of the game (Endings 1-4 should all get it).

Sophisticated Taste
You've drank half of Stardust's menu!
After you order a drink, it's added to your inventory so be sure to drink it. Keep track of which ones you've drank because the list is randomized.

Too Sophisticated
You've drank everything on Stardust's menu! Maybe you should take it easy?
Note: be sure to see Drinktionary below. If you want 100% achievements, it is worth ignoring Too Sophisticated until chapter 3 so you can knock out two achievements simultaneously.

Always The Best!
Try 10 different kinds of Hassy
There's a Hassy vending machine in the hospital lobby. Just keep on using the machine until you get all ten varieties. It will almost certainly take more than ten tries, but it will come eventually.

Observant
You've looked at 100 things!
Use the eye icon on stuff.

Hands-On
You've used 100 things!
Use the hand icon on stuff.

Crafty
You've used your items on 100 things!
Use your backpack icon and choose an item on stuff.

Loquacious
You've talked to 100 things!
Use the mouth icon on stuff. And people. But stuff counts too.

Persuasion
You convinced Lexi easily with your speechcraft
Select the correct conversation options when first meeting Lexi. "She's fine...", "Could you just...", "What happened...", You're going to...", "We'll have a better...".

Cybercracker
Fail to convince Lexi in Chapter One and find another solution
After failing to persuade Lexi to let you into Hayden's apartment, turn off power to the water pump and ask Alphie for water.

Hassy Hot Cups
Broke their will and cleared Market Street
Ask the Hassy Bar owner for permission to use the climate control ROM. Show her Fairlight's card. Go outside and interact with the ROM.

Well, That Worked
Start a riot at Market Street
Go one screen left of the protesters. Pick up the loose brick on the wall next to the billboard. Throw it at the police ROM.

Worst Cab Ride Ever
Successfully trapped your target
This guide shows how to stop the cab.

Negotiator
Played nice and worked things out
After you've stopped the cab, try talking to the punks.

Snitch
Called in for backup
After you've stopped the cab, call Lexi.

Unsociable
Struck out!
When trying to get into the VIP area of Stardust, give the Distant patron the drink they want and always select the first line in the dialogue option list. Do the same with the Distracted patron except select the last line. When they're both gone, look at the last patron to find out what was in their glass. Give them that drink and talk to them. Do not select the middle options ("What's the problem?", "Sounds pretty typical" and "Nothing is jerk proof"). Once all three are gone, the Distant patron returns and lets you in.

Waterlogged
Got washed out of the drainage tunnels
Unlocks during chapter six. Take enough wrong turns to fail the puzzle.

Sewer Shark
Successfully navigated the drainage tunnels on the first try
Unlocks during chapter six. The tunnel map is randomly generated, so follow the red pipes on the ceiling and look at the monitors for instructions.

Threat Neutralized
Got past the maintence ROMs without taking a scratch.
Unlocks during chapter six.

Terminated
Got killed by Dekker
When caught by Dekker, do not fire the electrolaser pistol. Alternately, you may earn this one by accident by failing the puzzle, running out of your four pistol shots.

Farewell, Old Friend
You finally found a use for it....
Just before the end of the game, at the Big Blue terminal where you connect Turing, use your spoiled milk from the apartment on Big Blue. Note that this will result in a Game Over, so save beforehand! Thanks to FruitNDoggie for the tip!

Hack the World
TOMCAT is your friend
Be nice to TOMCAT throughout the game. Unlocks in chapter five after Turing goes for a walk and TOMCAT talks about their past.

Son of a Gun
TOMCAT resents you
The opposite of the previous one. Be rude to TOMCAT throughout the game.

Empathetic
Jess warmed up to you and agreed to help you in your final quest
Be nice to Jess throughout the game.

Not a Cat Person?
Jess resented you and refused to help you in your final quest
The opposite of the previous one. Be rude to Jess throughout the game.

Cool Kid
The punks appreciated your patience and agreed to help you in your final quest
Be nice to Chad and Oliver throughout the game. After stopping the cab, talk to them instead of calling for backup.

Smell You Later
The punks refused to help you in your final quest
The opposite of the previous one. Be rude to Chad and Oliver throughout the game. After stopping the cab, call for backup instead of talking to them.

Junior Deputy
Lexi is your friend
Be nice to Lexi throughout the game. Unlocks in chapter six after disabling the security ROMs.

Bad Association
Lexi resents you
The opposite of the previous one. Be rude to Lexi throughout the game.

We're Alphanumeric!
At the end of it all, you became close friends with Turing.
Be nice to Turing throughout the game.

No Heart To Break
At the end of it all, you were resented by Turing.
The opposite of the previous one. Be rude to Turing throughout the game.

All Good Things
Completed Ending One
Be nice to Turing throughout the game, obtain all of Hayden's code and keep Turing from overloading in chapter six.
Correct conversation options before EX:
- "Turing, when are you..."
- "We're in this..."
- "Think about Fairlight..."
- "This isn't over..."
- "You and aunt Melody..."
- "Chad and Oliver..."

The Sacrifice
Completed Ending Two
Be nice to Turing throughout the game, fail to obtain all of Hayden's code and keep Turing from overloading (see All Good Things).
How to fail to obtain all code:
In chapter five, you break into the Parallax office by disguising yourself as a maintenance person. Fail the picture puzzle. Take the data from the console. When confronted by the receptionist, any lines seem to lead to the data being confiscated. I selected "Have you not...", "Just throwing out..." and "These need special...". It's a good idea to save before entering the office to easily get the other ending.

A New Blue
Completed Ending Three
Be rude to Turing throughout the game, obtain all of Hayden's code and keep Turing from overloading (see All Good Things).

Complicity
Completed Ending Four
Be rude to Turing throughout the game, fail to obtain all of Hayden's code (see The Sacrifice) and keep Turing from overloading (see All Good Things).

Flatline
Completed Ending Five
At the end of chapter six, select any conversation options that cause Turing to overload. They may have changed after the EX update, so save your game after beating Dekker and entering the room.

Clark Kent
You tried to actually do your job
At the beginning of chapter five you wake up and TOMCAT is in your apartment. Select "This is a bad idea..." -- this used to be an ending, but the ending was cut. In choosing this dialogue option your character says "I'm not Superman, I'm Clark Kent."

One More Good Day
Brought along an unhealthy snack
Take the spoiled milk from the refrigerator on the first day.

Playback
You used the headphones to listen to the soundtrack
Use the headphones in your menu to play back any song from the soundtrack.

Well-Read
Checked your inbox and the paper before you slept
Read your email and the news stories using your laptop on the first day.

Ding Dong Ditch
You got lost and annoyed the neighbors
Use (touch) one of the random doors in Hayden's apartment building until security throws you out. Note: this may end your game, so save beforehand!

Hydrophobic
Wilty is lucky Turing stepped in
Take a glass of water from the ROM in the park and attempt to water your plant.

Maybe It Just Needed A Little Love
You managed to keep the jade plant alive
When given the option, talk to Turing about your dead plant and they will revive it. Talk to your plant multiple times. See Botanist below.

Botanist
You brought Wilty back to outstanding health!
Talk kindly to Wilty multiple times before chapter 3. Intentionally stop back at home between missions to do this. It should have grown visibly by the end of chapter 1, and reached its final form by the end of chapter 2. The achievement should unlock when you talk to it in chapter 3.

You're Hopeless
Goodbye, Wilty
Do not talk to your plant more than once or twice.

Symmetry
You just can't leave plants well enough alone
Use (touch) the left potted plant on the windowsill in Zinn's office. This needs to be done the first time you visit the office, before talking to Zinn.

No, I Don't Feel You
That would have made sense, huh?
Give the headphones to 4Moolah for inspiration when asked for something that rhymes with tones.

Brick by Useless Brick
You puzzled without throwing garbage at your problems!
Thanks to Arynis for the tip on this one! There are a total of three puzzles where "throwing the brick" from your inventory can be a solution. The key here is to skip using it on all three while it is still in your inventory. Skip using brick on (1) the Genus protests Police ROM in Chapter 2 and (2) using the brick on the fire escape ladder outside Shotaro's apartment in the Media Arc. Third and finally, in Chapter 5, use the Zapper on the KCOB sign while you have the brick, instead of using the brick on the sign. You should get the achievement.

Maneki-Neko
You are very lucky!
In the Media Arc chapter (3 or 4), after you first gain access to Shotaro Otsuka's apartment, but before completing the events there, you must pet a stray cat in three locations. You can find this cat outside Shotaro's apartment, on Market Street in the bus shelter, and at CRASH next to the Violent Wing wrestler. The cat isn't guaranteed to be in any one place. Keep visiting these locations until the cat appears, and pet it at least once, maybe twice for good measure. People have reported issues with the cat disappearing in Market Street when it's snowing, so do this after starting a riot (see Well, That Worked).

Cardinal of Combat
You faced down the ghost in the machine.
Cardinal of Combat requires you to fully win the Megaphobe arcade game, located in Stardust. You have to shoot through the regular baddies with perfect or near-perfect health and then a creepy Ghost in the Machine boss comes out. You have to keep grabbing health and energy packs to get by, but you just keep going until you win. Eventually, in the end-form of the boss, you run out of bullets but are allowed to keep firing anyway, so get ready to frantically click before you run out of health in the end. Win, and the achievement is yours!

Groceries
That's one way to stock your fridge.
You need to stock your home fridge with fresh milk. To do this, during the Media arc (either chapter 3 or 4), when you reach TMI Entertainment, you have to get kicked out once by wasting Charlie Nova's time. To do this, choose dialogue options other than the ones where you use wrong names (Chuck, Chip, etc). Sympathy will kick you out. At that point, Turing suggests serving coffee to Sympathy. And sitting right out there is a cup of coffee and a fresh carton of milk. Use your spoiled milk on the coffee (if it's not in your inventory, run home and get it), then take the fresh milk for your own use. The spoiled coffee makes Sympathy sick, allowing you to finish the story mission with Charlie. When you're done, go back home and place the fresh milk in your fridge.

Drinktionary
You've been on every drunken escapade
During Media arc or Vincent arc (chapters 3 & 4), keep getting drunk until you've passed out in each of the following locations.

1. Home
2. Right outside Stardust
3. Hospital
4. Golden Gate Park
5. Market Street
6. NSFPD (police dept)

There doesn't seem to be any rhyme or reason. Just keep drinking and eventually you'll pass out at all six locations. This cannot be done until the start of chapter 3, and if any of these locations aren't available on your world map, you can't pass out there. Also, highly recommended that achievement hunters wait to do Too Sophisticated until chapter 3 so they can work on it with this achievement at the same time.

Jobber
You've learned a lot of wrestling moves!
In Media Arc chapter (3 or 4), when you first gain access to CRASH, keep using the hand/touch option on the wrestler on the right. The game will continue to warn you that if you're not careful you're going to have a wrestling move used on you. There are a total of 10-12 wrestling moves. Sometimes they repeat. Just keep selecting the touch icon over and over.

Stop The Violence
Provoke a tough guy in the wrong part of town
Pull your gun on Nonya repeatedly while in his store. Note that this will result in a Game Over, so save beforehand! Thanks to FruitNDoggie for the tip!

Good Listener
Find and listen through all of Turing's lectures
1. Look at Hayden's computer when first visiting his apartment. Continue the conversation.
2. In chapter 1, when Turing first asks about Wilty, pursue that line of dialogue (and the Mildew one) before saying "We have more important things to worry about."
3. Look at leftmost tree in Golden Gate Park during chapter 1, and respond to Turing with "What did you say?" Never interrupt the conversation.
4. Outside Dogpatch, look at the large colorful graffiti. Don't end the conversation early.
5. In the beginning of the Media arc chapter at KCOB, say "How so?". Then keep picking the top option.
Note: these four must be heard in progression, on the same save file. Order might not matter for the park tree, but the others happen in a specific order at specific moments.

To unlock the DLC "EX" Scenario, you have to have at least one save file / character that has cleared Ending 1 (presumably the "canon" ending). Once this has been done, as of the Jan 22, 2016 patch to ver 1.2, you can click "EX" in the top-left of the main menu for the "Endless Christmas" EX scenario.

There is one achievement associated with this new content. It is:

Yule Be Back!
Explored the city’s happenings on Christmas day.
Go to each zone available and talk to all of the major characters. Once you've spoken to all of them, the achievement will unlock. Note that you must go to every zone, not just the one with character icons above them (one person unlocked the achievement after visiting TMI Ent. last and speaking with Sympathy).