First things first, there are a few missable achievements to be aware of so as not to lock them out of your playthrough:

• Hedging My Bets - Do as you're told (for now).
  Collect all 49 Red Sigils before entering the Tower.

• Thorough Researcher - Collect all pieces of written information.
  This is related to Terminals - They will beep at you, use each terminal and read all documents. Press B to see which have been read, see Collectables Part Two for full list.

• QR Reader - See what the others have to say.
  Around the hubs and puzzles there will be QR codes, read any you see until this achievement unlocks.

• Solipsist - Get everything on your own.
  Do not use the Messenger help (the altars in each puzzle, just ignore them until told otherwise)

• LOL - Laugh at the pointlessness of existence.
  When you are at a door puzzle with a square and two Ls, before solving the puzzle create LOL.

A note on Terminals

There are two options:
Option 1: When talking to the terminals go through the conversations as you please for the most part but be aware of the conversation option mentioned below option 2.

Option 2: Do not touch the Terminals until you have all the 49 red sigils. Then reload the backup prior to getting the last sigil and continue as per below.

Go through the terminals to activate the conversations until you see:

• Imagine that in a few hours from now you climb to the top of the tower. There's a flash of light, then Magic happens, then you find yourself in the real world, living whatever you take to be a normal life there. What would you do then?

Then select the response 'What's Right' continue on as below.

Follow the roadmap and once you are in Temple C, eventually you will have a conversation with the responses being 'What holes? There are no holes' and 'I accept that some of my beliefs face difficult challenges'. When you have these options, it is time to tackle the Terminal missable achievements - see the Stars section below.

This roadmap will assume you picked option 1, personally I played through right up to Temple C and collected all red sigils without any conversation prompts, I may have got lucky!

There are plenty of YouTube videos for any puzzles or star locations you are stuck on so I haven't included any puzzle solutions. I did the majority myself but there are some which are a bit tricky (for example I did not realise I could use a jammer on fans...). There are a number of possibilities with some puzzles. This is a roadmap to guide you through a playthrough for all achievements in the most effective order.

Starting Area
Read all entries on the Terminals.
Complete all puzzles in the start area.

Temple A
Once you leave the start area you will be in Temple A.

When in a puzzle for a while Elohim will say you can leave and try something else, leave the puzzle, you will unlock:

Know Your Limits
Accept Elohim's wisdom.


Around the hub areas will be white paint pots (there are a number of random spawn points). When you see one pick it up, find a wall and paint a message. You will earn:

Leave Your Mark
Tell the others what you think.


Complete all puzzles in hub areas 1-7 picking up any Stars.

Collecting the yellow sigils will unlock Connectors and Hexahedrons activated within Temple A itself. Collect the green sigils to unlock the lift to exit Temple A.

Temple B
Exit to the open main hub area outside temple A, turn left for Temple B. Remember to read the QR codes dotted around the areas. Use the lift to go down.

Collecting the yellow sigils will unlock Fans and Recorder activated within Temple B main area.

Complete all puzzles in hub areas 1-7 picking up any Stars.

Temple C
Exit to the open main hub area, go straight ahead to Temple C, use the lift.

You should have enough yellow sigils to unlock the final device which is to the left at the end of the main corridor.

Messenger Islands
Each Temple has a doorway block by wooden barriers, these open up the three Messenger Islands.

In Temple C, down the corridor to the right of the big doors there is a emergency axe on the wall, use it to cut down the blocked doorway to your right to unlock:

Break Down Barriers
That's what axes are for!


Enter the portal to unlock:

Sacred Grounds
Find a Messenger's abode.


Solve the puzzle to access the tomb and activate the messenger. There is also a Star here to be collected.

Read full paragraph before continuing: Return to Temple C using the portal. Pick up the axe again and go up in the lift to Temple A and B to smash the barriers. Enter each portal to solve the messenger island puzzles earning three helpers in total. Now ignore these and do not use any alter in any puzzle otherwise you will be locked out of a later achievement.

Back to Temple C

When doing one of the red puzzles, stay in the puzzle for more than 12 minutes moving and jumping around, when Elohim says "My child, there is no shame in seeking another path" complete the puzzle and you will earn:

Extreme Persistence Detected
Try, fail, try again, fail again, eventually succeed.


During a puzzle with a recorder, puzzle A Ditch and a Fence in hub area C2 is one. First pick up the paint bucket from next to the purple door in the hub area, enter the puzzle and record yourself painting a QR message on the wall, play the recording to read the message and unlock:

Split Personality
Communicate with your double.


Complete all puzzles in hub areas 1-6 picking up any Stars. We will come back to C7.

Stars
Go back through each Temple and collect all stars you are missing, use the boards outside each hub area to see which you need. There are 30 in total but you can't get them all yet. The most you would need at this point is 27. There are two in the tower which you cannot go in yet otherwise you void another achievement. There is also one in level C7 which you don't need at this point.

Continue collecting stars until you have the conversation options below.

Now create a new checkpoint save by completing only one puzzle in Temple C level 7.

You should be able to earn the terminal conversation achievements in the following order. Wait for the achievements to pop up without leaving the terminal, if you leave the terminal it may autosave to quick for you to quit and reload, take it slow when choosing the options.

You will have two options What holes? There are no holes or I accept that some of my beliefs face difficult challenges.

Press The Serpent
Expose the flaws in the code.


To earn choose the following:

• I accept that some of my beliefs face difficult challenges.
  
• I equated personhood with humanity, which was a mistake.
  
• There's nothing else I'm prepared to doubt quite yet.
  
• I am unique.
  
• So long as I might have chosen otherwise I can make a difference.
  
• Does the path being predetermined mean it isn't worth taking?
  
• Do you think there can be no new ideas? Nothing better?
  
• If there's no point in anything, why are you talking to me?
  
• Are you avoiding the question?
  
• (finish the conversation)

Once the achievement has popped, exit the game and restore from last backup (not checkpoint) to earn:

Last Stable Version
Restore a backup version of yourself.


Activate the terminal again to earn:

Silence The Serpent
Do not allow the serpent to fill you with doubt.


To earn choose the following:

• What holes? There are no holes.
  
• No, I stand by everything I've said. These matters are beyond doubt.
  
• I am special.
  
• So long as I have a mind I can make a difference.
  
• /banish
  
• I'm not sorry. Continue.
  
• You shouldn't have ever doubted me, snake.
  
• Resume.
  
• exit

You have to earn the above two achievements first otherwise the following achievement will lock those out. Once the achievement has popped, exit the game and restore from last backup.

Activate the terminal again to earn:

Deal With The Deceiver
Strike a deal.


To earn choose the following:

• I accept that some of my beliefs face difficult challenges.
  
• I equated personhood with humanity, which was a mistake.
  
• I claimed to have knowledge about the world that I simply can't confirm.
  
• No, I see now everything I've argued was flawed.
  
• I refuse to trust anyone, including myself.
  
• We do.

Complete all puzzles in level 7 picking up the final Temple Star.

You should now have all 49 red sigils. As long as you did not go in the Tower or request any messenger help you will earn:

Hedging My Bets
Do as you're told (for now).


Solipsist
Get everything on your own.


As soon as this achievement pops, exit the game and restore from backup (not checkpoint) to before you completed the last puzzle, it will not be the top of the list so try the backup beneath the top one.

Go into the unsolved puzzle and use the messenger alter to receive help.

Help From Above
Receive guidance from Elohim's messengers.


** If the reload does not work see extra short playthrough at the end of the roadmap **

At this point during Temple C the glowing doors will open go through them and use the Terminal at the top of the stairs to unlock ending one:

Eternal Life
It's not for everyone!


After the credits, restore from backup to continue.

Tower
Enter the Tower, you will unlock:

Off The Radar
A little curiosity never killed the cat.


Enter the lift, each floor will have a door puzzle, a normal puzzle and terminals on floors 1-4.

Final two stars

After solving the Tower Level 1 puzzle you will need both connectors and the axe from Temple C. Explore around the back of the tower to find the star using the axe and connectors.

After opening the red sigil door on floor 5 go into the next building and look out the window. Go out onto the narrow ledge and down to the third one. Turn around and head towards where the pigeons are and out to the end of the beam. Look down at the tower building below and walk of the edge, you will be in a secret room in tower level 3 where the final star is located.

Ending Two
Go back up the tower until you reach floor five. Proceed up to the top of the tower and stop as soon as you unlock:

On The Edge
Reach the top.



Do not walk any further but turn around and go all the way back down to the bottom of the tower, go to Temple C through the glowing doors and use the terminal to unlock ending two:

Changed My Mind.
It is never too late to accept Elohim's forgiveness.



Ending Three
After the credits, restore from backup to continue.

Go to the top of the tower and complete the final tower puzzle with the help of a friend. After the puzzle use the terminal and choose to complete the deal you made earlier, this will unlock ending three:

Free Will
Bring the end of your generations.


And

Take It With You
Internalise the voice of doubt.


After the credits, restore from backup to continue.

Now you have unlocked Tower level 5, time to clean up the voice recordings you have missed:

A Good Listener
Listen to all she has to say.


For this achievement you need to find all 22 Time Capsule voice recordings (floating glowing icons scattered around the worlds). You will have most of these, you can check the in game list to find what you are missing:

• 1 - A2, go forward from the start
• 2 - A4, go forward from the start
• 3 - A5, Forward and left from the start, its behind a wall
• 4 - A7, next to the start

• 5 - B2, turn around at the start
• 6 - B4, go forward from the start
• 7 - B7, To the right of Big Lump of Mine
• 8 - B7, To the left of Bouncing Side by Side

• 9 - C1, Head to the bridge it on the left of the road
• 10 - C3, next to the start
• 11 - C5, To the left of the level
• 12 - C6, To right of the level
• 13 - C7, To right of the level
• 14 - C7, To the back left of the level behind a wall

• 15 - Messenger Island C, in the middle of the red and blue transmitters
• 16 - Messenger Island A, next to a fan
• 17 - Messenger Island B, Go behind the tomb building

• 18 - Tower Floor 1, outside the lift
• 19 - Tower Floor 2, left of the puzzle door
• 20 - Tower Floor 3, before the puzzle
• 21 - Tower Floor 4, left of the puzzle door
• 22 - Tower Floor 5, before the puzzle

Star Doors

You should have all 30 stars. Each Temple has a Star door which should now be open. These are star hub areas A8, B8 and C8.

When entering each star hub area note down the code you can see in front of you (it's random for everyone but will look like 6**, you need a three digit code)

Complete all the grey sigil puzzles to eventually earn enough to unlock Tower floor 6.
This is required for the final ending.

This is a good time to finish up any terminals you have missed.

Thorough Researcher
Collect all pieces of written information.


Check your in game list for any you are missing. There are terminals:

• At the start of every hub area (A1-7, B1-7 and C1-7)
  
• Next to A, B and C lifts
  
• Floors 1-4 of the tower
  
• One each behind the Star doors A8, B8 and C8

Additional extra and hidden terminals:

• Terminal A-2 Extra: Go through the destroyed coliseum until you get to the water. Go left and follow it until you find the terminal.
  
• Terminal A-6 Extra - Go forward from the start, when you reach a wall, turn left
  
• Terminal A-6 Extra 2 - Go forward from the start, when you reach a wall, turn right. You are looking for cube near some rubble. Pick up the cube and go to the wall in between 'Mobile Minefield' and 'Deception'. Climb over the wall using the cube to reach the terminal and a star.
  
• Terminal B-1 Extra - Head right and up some stairs, take a left.
  
• Terminal B-3 Extra - Turn around and go towards the wall, its on the left
  
• Terminal B-5 Extra - Turn right, follow the water and you will see it on the other side of the island.
  
• Terminal B-7 Extra - From the door of 'Whole Lotta Jamming' turn right, it's on the far left side of the large structure ahead of you.
  
• Terminal C-1 Extra - From the start go to the bridge, take a right and follow the water.
  
• Terminal C-5 Extra - Head forward to the puzzle's door, take a right then a left at the corner.
  
• Land C Elevator Hidden - Behind the building in World C.

Now for the final 100% ending.

Once you have your three digit code return to Tower floor one, solve the puzzle again and use the terminal to unlock floor six using your code. Use the lift to go to floor six, solve the final door puzzle with the grey sigils and enjoy the final ending as well as unlocking:

Blessed Messenger
Solve every mystery in every land, that you might aid those who walk in your footsteps.


Go back to the main menu to start the next part of the Talos story and obtain the remaining three achievements.

There is one missable achievement and three story achievements in the DLC.

Although there are no achievements related to the terminals to progress you have to interact with each one after each puzzle. Read everything. The details in these terminals are very different to the main game and do offer more insight to what is happening in this part of the story. Your choices have no relevance to the achievements.

For the missable achievement you need to collect 10 stars, collect them while completing the puzzles. Once you have 10 stars go behind hub building 4 until you see an island you can jump down to, use the fans to hop from island to island until you reach one, you may have to jump down to it, with a gold door like puzzle. Use the teleporter to an area with seven silver puzzles. When they are complete return to the hub area centre and use the stairs off the edge to open Admin's cell. You will unlock:

Free Admin
Rescue Admin from his prison cell.


Finish any remaining puzzles and use the terminal to ascend finishing the game and earning your final achievement.

This section lists the speedrun requirements to unlock Help From Above achievement if it didn't work for you, depending on your speed at solving the puzzles this should take about half an hour to an hour:

• Speed run through the starting area to reach Temple A. Complete the green sigil puzzles in Temple A to unlock the lift for A and B. Complete the yellow sigils to unlock the connector and hexahedron.
  
• In Temple B complete the green sigils to unlock Temple C. You may need to unlock the fan for some of the green puzzles.
  
• Once you have access to Temple C, proceed to the Axe and enter the messenger island, solve the puzzle to earn the first messenger helper.
  
• Go back to one of the puzzles in any temple where you have the required devices and use the messenger alter.

Help From Above
Receive guidance from Elohim's messengers.


Once this is done, that should be game complete!