* Spoilers below *

The game requires at least one full playthough (in Hardcore mode), as well as several false starts and playing through arena mode. You will likely want to play through at least twice, the first time on Normal mode and the second on Hardcore mode.

Achievements in italics can be ignored if you are going for 100% because you will need to have gotten them to get others.

These are unmissable if you complete the game once:

First of Many - Find one piece of location data.

Glorious Monuments - Unlock the second tier of derelicts.

Majestic Monoliths - Unlock the third tier of derelicts.

You Made It - Reach the Mothership.

Welcome, Citizen! - Enter the Mirror World. Beat the campaign.

These require a partial or full campaign run to achieve. These are among the hardest and most time consuming because they take a full run. I suggest going for the full-run achievements on your first playthrough if possible.

No Fear of Zombies - Kill Necroguard without losing a character or retreating. You should get this in normal play by defeating a necroguard enemy. This is missable if you lose a character or retreat. It may be possible to avoid all necroguard fights, but there's no need, they're stronger then average, but not unbeatable. You can come back to them when you're stronger if one if giving you trouble.

Energy Adept - Never run out of energy during a single playthrough. Return to the home base whenever you get low on energy. Make sure you have energy cannisters as backup. Don't start a fight if you're low on energy.

No Step Back - Complete the game without ever retreating from combat. Don't click the retreat button for the whole campaign. Best done on normal mode.

I'll Buy My Own World - Have a cash balance of 100,000 credits. There are two ways to get this. 1) If you have one leader in your party, take the Negotiator ability that gives you bonus credits. Play a full campaign and you should get to 100,000 or close to it if you clear all of the derelicts and don't spend too much. 2) [credit goes to I am Groot! in the forums] If you don't want to play a full campaign, make a party with 3 leaders and give them all Negotiator. Now you can buy and sell back items at a profit so you can get to 100,000 by just visiting the store.

Executive and Greedy - Complete all side missions on a single playthrough. Each derelict has one or more side quests / missions in addition to the main mission of securing the derelict's location data. To get this achievement you must visit all derelicts and find and complete each side quest in one playthrough. This should pop before getting to the mothership if you save the mothership for last. When you are setting out from the station, you can see if there are any incomplete missions for each derelict.

True Scavenger - Beat the game on Hardcore. I suggest playing on Normal mode first to learn the game. See the forums for discussions of good team builds and overall strategies. I used a leader, bruiser, medic.

There is usually one or more side quest per derelict in addition to the main mission of getting the location data. Sometimes they are associated with contracts from the bar. They can often be resolved with no fighting. Some of them have achievements associated with them and some have two mutually exclusive achievements associated with it. Not all side quests are available each playthrough so you may need multiple playthroughs to get all of these. There is an achievement called Executive and Greedy, listed above, for completing all available side quests in a single playthough.
(Mission Log name; mission origin; partial list of derelict level where mission was encountered)

Diligent Trashman - Collect 6 piles of trash for Arberi. You only need 3 piles to complete the mission. Keep searching until you get 6 before reporting back to Arberi to get the achievement.
(Tidying Up; derelict; lvl 1-3)

Transhumanist - Help Espinoch transcend his flesh existence. Complete mission involving Espinoch.
(Fantastic Surrogate; location data; lvl 2-3)

Standard Field Procedure - Collect and deliver fungus to Chapeau. Complete mission involving Chapeau.
(Standard Field Procedure; derelict; lvl 2)

The following two are mutually exclusive, either path completes the mission. Make a save and return to it to get both in a single playthrough. You will get a mission from Salome who is being harassed by Parsons-T. Attack and kill Parsons-T to get Toil and tell Parsons-T about Salome to get Parsimony.
Toil - Destroy Parson-T for Salome.
Parsimony - Locate Salome and expose her to Parson-T.
(Documents Please; station contract; lvl 2-3)

Appetite Ruined - Learn the secrets of eating in a space suit. Random derelict encounter with Goodis.
(N/A; derelict; any)

This is not a side quest, but in one derelict you will find a rival scavenger group. The following two achievements are mutually exclusive. You should have the option to talk/trade or attack. If you talk to them, the option to attack is removed. Make a save and return to it to get both in a single playthrough. (If going for Smooth Talker, you must be in normal movement; if you are in stealth or rush, you enter into combat without a chance to talk. Thanks to Slick.)
Smooth Talker - Get friendly with a rival scavenger group.
This Ship is Too Small for Both of Us - Vanquish a rival scavenger group.

Not Like This - Visit the Mirror Worlds the bad way. On many derelicts after the starting ones, there are roving groups of martyrs. They show as enemies on the scanner, but they will not attack you, at least at first. You have the option to attack them. They are fairly difficult fights, so getting this achievement may be best attempted towards the end of the campaign. Once you attack and defeat a handful of groups of martyrs, you will get the option to surrender. This option only happens once! You must surrender to get the achievement. If you don't surrender, any other martyr groups will attack without conversation. Note that this ends the game so don't try this on Hardcore and make sure you have a save to return to. Or wait until you have finished a full run and then return to the derelicts to get this.

Flawless Victory - Win a combat encounter without receiving any damage. Will likely happen early and often, this is the most common achievement among Steam players.

No Time Wasted - Win a combat encounter in one round. Should happen in normal play. To ensure it happens, leave one enemy group alone in an early derelict and then come back to it when you're stronger.

Houdini - Play 4 or more cards on a single turn. Certain cards allow you to play more cards. This is easier to get in energy rooms because you sometimes get energized (extra free action). There are also many class skills and bonuses which may grant extra card plays. If you pass your turn, you save that energy for the next turn (I have not verified if this counts towards the achievement).

Da Blast! - Deal over 100 points of damage with a single attack. Will likely happen normally towards the end of the game. I think this has to be one attack versus one enemy. Some easy ways to increase damage: focus damage, Tracker's mark skill, or boost critical damage. It's possible to do over 1000 damage, so hitting 100 should be no problem.

Massive Impact - Kill multiple enemies with one attack. Should happen in normal play. Use a weapon or skill (such as grenades or spread weapons) that targets multiple enemies at a time and finish off two in the same attack. As with No Time Wasted, you can leave one enemy group alone in an early derelict and then come back to it when you're stronger.

Impenetrable - Have over 200 shield points on a character in combat. Technicians and tech cores have cards which allow for adding shielding above normal resting shield level. Keep stacking until you get to 200 shields. This goes well with the Trench Warfare achievement below.

Trench Warfare - Have a combat encounter that lasts for 50 rounds. This requires some planning. You want to find a combat encounter where the enemy can't harm you (or you can replenish shields faster than they can be taken down), but at the same time you can't run out of energy or let the enemy kill themselves through self-damage. Ideally, you would start combat with near full energy. Don't throw out a Taunt Bot, because that increases the chance the enemy misfires. Then just keep hitting end turn until you get to 50 turns.

Errand Boy - Complete a contract. You must take one of the contracts available at the Lair and complete it (gather a certain # of junk parts). Pay attention to the items which are part of contracts and don't sell them as junk.

Prepared for Anything - Have all single character's equipment slots filled. Each character has 4 core slots and each of those has 2 mod slots for a total of 12 slots to fill. You should have enough items by looting fallen enemies, random items found on derelicts, and buying from the shop, to get this fairly early on. I think I had it by the time my characters were level 3.

Fully Proficient - Max out an ability. Class abilities only have two or three slots, so this should be easy to get early.

Try'em All - Advance at least one character of each class by 2 levels. The simple way to get this is to play once on Normal and once on Hardcore and select the original 6 classes (scrapper, tracker, bruiser, medic, technician, and leader). (The DLC does not factor into this achievement. You do not not need to advance the miner and inventor; thanks to Xeloses. You do not need to start the characters at 1st level; thanks to Lhetre.)

Never Too Versatile - Pick a specialization for a character. Happens at level 4.

Scavenger Elite - Get a character to level 10. Will likely happen before you beat the game as long as you don't skip too many encounters along the way.

Overskilled - Raise a character's skill to 200. Will likely happen normally in campaign mode. Some classes have abilities that add to skill level and otherwise you can stack cores and mods that add skill points. I think a Technician with two tech cores is the easiest way to get this.

Shiny! - Find and equip an Illustrious piece of gear. Illustrious gear has one very strong perk shown in yellow in the item stat box. Random, but should happen in normal play. Scrappers are more likely to find these.

Boffin - Build all research upgrades at the Research Workshop; there are 18 available. Note that you have to scroll down to see them all. The total cost is 19,450 credits. I had all of the upgrades by the time my characters were level 6 or so, but this will largely be dependent on how much healing you need to do, how much you earn and spend at the shop, and how much you value the upgrades. (The DLC adds upgrades for crafting and implants. With the DLC, there are 26 upgrades with a total cost of 22,700.)

These are based on the energy resource. You start with 1000 energy and can get up to 2000 by buying research upgrades. Energy is spent moving, scanning, clearing debris, and in combat. When energy depletes, you will automatically use an energy cannister if you have one in your inventory (they come in 100, 300, and 600 energy sizes). If you run out of energy and cannisters, your shields will run down and then your health.

No Life Without Sacrifice - Convert a piece of loot into energy. Right click on any piece of junk and choose to convert to energy.

Oxygen Not Included - Lose an entire party due to energy depletion. Load up an old save and sell off all energy cannisters. Go to a derelict you've cleaned out and keep scanning until you get below ~50 energy and then walk around until your shields deplete and then keep walking around until you die.

Close Call - Successfully return to the station after running out of energy. Run out of energy like in Oxygen Not Included above, but go back to the station after running out of energy (and cannisters if you have any in your inventory).

Achievements for things you probably wouldn't do in the normal course of playing the game.

Nobody Is Irreplaceable - Dismiss a character. Go to the den and dismiss a character.

Let's Try an Intern - Hire a mercenary. Go to the den and hire a character. Must have one of your 3 slots open due to the death of a character or through dismissal (see Nobody Is Irreplaceable above).

Danger Zone - Enter a derelict two levels higher than your highest ranked character. When you unlock the second tier of derelicts, hopefully you are level 2 and now have access to level 4 derelicts. If not, you might get the chance as you unlock derelicts later.

Professional Pride - Go to a derelict with three characters of the same class. Generally not a good idea for a full campaign. Start a new game, select the same class for all 3 characters, enter a derelict, delete the save. Goes well with Uncontrollables below.

Uncontrollables - Go to a derelict with three aggressive characters. Generally not a good idea for a full campaign. Start a new game, select aggressive (+5% melee damage) for all 3 characters, enter a derelict, delete the save. Goes well with Professional Pride above.

For some inexplicable reason, developers include achievements which are the opposite of achievements. Perhaps they include them for data gathering?

Rust in Peace - Lose a character in combat. Will likely happen in normal play.

Fresh Loot - Lose an entire party in combat. Don't try this in Hardcore mode. May happen in normal play. If you want to get it, start a new game, get into combat, don't play any cards.

Tenacity - Win a fight with only one character remaining. This is actaully hard to do on purpose. Load up an old save in normal mode and find a challenging fight. Kill all but one and then stop playing cards until you are down to one character left.

Animate - Revive a fallen character. Get a character killed and the med bay will give you the option of bringing them back, assuming you don't wipe the whole party.

The Real Pain - Spend a total of 5000 credits on medical costs. In the course of a full campaign playthrough, you will likely get this unless you are doing very well. If you want to get this, maybe don't have a medic in the group. You can always load an old save and take damage on purpose.

Game Over! - Lose an entire party in Hardcore mode. After you beat Hardcore mode, you can load your most recent save and get them killed.

You must win at arena mode to unlock these achievements:

Bronze Medal - Advance past the 5th encounter in Arena mode.

Silver Medal - Advance past the 10th encounter in Arena mode.

Gold Medal - Advance past the 15th encounter in Arena mode.

Arena Champion - Beat Arena mode.

The arena rules:

• No returning to base, no shop, no med bay.
  
• 20 consecutive fights.
  
• At the start, you gain a level and get a batch of loot after every second fight. Later the frequency changes to 3 or 4 fights and towards the end it becomes more frequent again. By the 19th fight you should be 10th level with access to 10th level items.
  
• There is a healing computer after the 10th fight.
  
• You spend energy as in the main game, but it's plentiful so no need to worry.

You can save at any time, as long as you're not currently in a fight. This means you can save, fight, and reload if it goes poorly. You can do each fight as many times as you want and make new save slots if you think you might want to go back a few fights and make different choices.

I recommend playing through the campaign first so that you learn the enemies, status effects, classes, and overall strategies. I recommend a balanced crew: one leader or scrapper; one technician or medic; one bruiser or tracker. I didn't find scrappers that useful. Bruisers are fine, but if the enemy counters melee attacks, the bruiser has no way to attack. I won with leader, tracker, technician.

There are two DLC and if you have the Definitive Edition then you have both. I don't know which of these goes with which DLC so if for some reason you only have one DLC then just ignore the ones you don't have access to.

Bounty Hunter - Finish a bounty quest. In the Lair, where you get contracts, some contracts will be bounties on criminals hiding or hunting on a derelict. The bounty will let you know which derelict the criminal is on. Here are some bounties: The Scav Charmer, The Pyromancer, The Scourge Herder, Partners in Crime, The Foul Practitioner, The Red Menace, The Skinkmistress, Emissary of Assimilation, A Morbid Crew.

Station Defender - Successfully fend off a station raid. Station raids are random events that may trigger when leaving the station. Number of waves may vary, from 2 to 7. I think this event is enabled in the middle of the game, starting at character level 4 or so.

Jackpot - Get the featured item from the shady dealer. The shady dealer is another random station event. You must gamble and get a high quality item. When you see the shady dealer, don't engage him. Save your game and then try to get the jackpot as many times as it takes by reloading.

Enhancements for Everyone - Have two implants for each crew member. At the start, each crew can get one implant. There is research for 1250 credits that will allow two implants.

The rest of these are missions / side quests which may appear on derelicts:
(Mission Log name; mission origin; partial list of derelict level where mission was encountered)

Quiz Master - Answer correctly all three questions asked by Derelictkeeper. You may randomly meet the titular quiz master as a side quest. If you navigate the dialogue, he will ask three questions and if you get them all correct you will get a reward and this achievement. See discussion here: https://gtm.steamproxy.vip/app/698640/discussions/0/3175526477750387902/
(Quiz Master; derelict; any)

The following two are mutually exclusive, either path completes the quest. Make a save and return to it to get both in a single playthrough. You will get a side quest from Tarack, a robot janitor, who is wants to fire a rocket. Tarack will give you an ID to make the rocket at a console. Jill is hiding in the rocket. Saving Jill was available for me as a contract at the very beginning of a run on the first derelict.
Stunt Assistant - Help Jill perform her stunt. You must pass a tech challenge to get access to this option at the console, choose 'transportation'. This may require a technician in your squad.
Proper Ordnance - Blow up Jill and her space ship. Choose 'destruction' when configuring the missile at the console.
(Rocket Away; station contract; lvl 1-3)

The following two are mutually exclusive, either path completes the quest. Make a save and return to it to get both in a single playthrough. This mission is started as a contract on the station called Necroscience. It was available to me on a level 6 derelict.
Slavery Prevented - Save the expedition scientists from slavery.
Doomed to Slavery - Allow the Naega to take the expedition scientists as slaves.
(Necroscience; station contract; lvl 4-6)

Rite Denied - Save the Prince. Find a cluster of Triumvirate soldiers with Gamenon. He will give you a mission to free them; they are trapped by three hull breaches. On the last hull breach, a strong necroguard is trying to perform a ritual involving a prince. The necroguard will offer you a powerful item if you let him perform the ritual, but you need to stop the ritual and beat the necroguard twice to get the achievement.
(Breach Duty; derelict; lvl 8-9)

Disappearance Act - Convince Mag to swallow itself. Yumruk gives you a quest to summon the great Mag. Once you do, choose the peaceful options "Worshipper" "You're not really evil." "I'm ready to cause you pain." Then there should be 5 options, select the one that suggests Mag devour itself to unlock the achievement.
(The Power of Blood; derelict; lvl 4-7)

The following two are mutually exclusive, either path completes the quest. Make a save and return to it to get both in a single playthrough. You will find Rake AI, an orb bot looking to be implanted in a creature. The first two locations he suggests fail, and at the third there's an idle robot. When you put Rake in the robot, a Serpentwurm eats it. If you kill the serpentwurm, Rake synchronizes with the robot and if you don't it synchronizes with the serpentwurm.
Peculiar Vessel - Help Rake AI to synchronize with the Serpentwurm. Choose "let Rake dissolve in the creature's belly".
A Suitable Vessel - Help Rake AI to synchronize with the dormant robot. Choose "attack the beast". After killing the serpentwurm, you have the choice of snatching the location data or not. If you choose to snatch it, you need to pass a tech challenge to grab it and still have Rake synchronize. You can also choose to give up on the location data which means Rake successfully synchronizes.
(N/A; location data; lvl 5-7)

Live Fuel - Feed pirates as fuel to a derelict's power generator. A console in an irradiated dome will ask you for "fuel". Nearby, there should be another stationary triangle quest marker that is a gang of pirates holding a combat tournament. Win all three rounds and you become king pirate. Lead the pirates back to the console and have them go in first. They will turn into zombies and chase you; you need 350 energy to escape them; not sure what happens if you're caught. The console will thank you and offer the location data or some other reward, but you should already have the achievement.
(N/A; location data; lvl 8-9)