Slaver
Kill the Archon Slayer


This is the first boss in the game.

Celestial
Kill the Celestial Beast


This boss is located in Arcology, and is the second boss in the game.

Congregators
Kill the Arisen Congregators


This boss is located in Sohn District, in one of the two areas directly past the Celestial Beast boss fight.

Artillery
Kill the Artillery


This boss is located in Ikari Walkways – This boss is along the other path after the Celestial Beast boss fight.

Companion
Equip the Omnicube and use a program.


The Omnicube is located directly after the Archon Slayer bossfight, just before the door to the observatory. You can use any program for this achievement.

Event Horizon
Activate the Observatory.


After defeating the Archon Slayer, proceed to the Observatory and activate the main button here to open the shutters and activate the rift.

Replicator
Craft an item with a blueprint.


In the observatory, once you acquire a blueprint, use the 3d Printer to craft it.

Gate to the Stars
Synchronize a Breach.


Use a Breach Synchronizer at any Breach in the game. One can be found if you are in the Obseravtory, climb to the 3rd level, and make your way to the far right side. At the cliff, look down to see a small metal walkway, follow this to an Exo-Lift and climb to the top of the Observatory. Ahead, you’ll see 3 short-medium-large columns, jump up these, and at the very top of the Observatory’s dome, you can find your first Breach Synchronizer.

Surge of Power
Equip an upgrade chip.


In the Observatory, socket any Conductor into a weapon at the upgrade station directly behind the Breach.

Strangest Thing
Summoned a friendly… pet?


This seems to be a bit… slippery when it comes to working, but, anywhere in game, with no menu up, input the Konami Code using the D-Pad. Up-Up-Down-Down-Left-Right-Left-Right-B-A-Start.

Slayer
Defeat a horde.


This achievement is tied to the clock and events you can find scattered across the space station. The one I found easiest to get to early is in Sohn District. After the corpse pile Breach, go out to the steps and head left. You’ll face a patrolling Daemon, and just past him is a large gate with a small blue door next to it. Open this gate using the button located inside the smaller door. Now, during Hell Hours (2-4am, 8-10pm) an orange fog wall should appear where the large gate door opened. Enter this, defeat the ambush, profit.

It’s full of stars
Find a monolith and explore the Underworld.


There are multiple monoliths in this game, but by far the easiest one to find is within the Arisen Dominion (This area has two!). Just before you fight Undisturbed Defas Nemundis, you must first speak to the Council. In the hallway leading to the Council is a monolith. Interact with it and enter it, and while inside, use this to do the next achievement as well.

Show me what you got
Talk to a cosmic God.


Once inside, assuming you’ve spoken to the Council, the door to Nemundis will be open, speak with him, earn this achievement, and finish his dialogue to do the next achievement as well.

I’m still worthy
Gain the trust of a Cosmic God.


For this achievement, you must complete one of the three quests for a cosmic God. For this, we’ll use Nemundis again. He asks you to collect 10 Fragments of Daemon. To do this easily, go back to Sohn District, exactly where I mentioned in the Slayer Achievement, and access the corpse pile Breach, then, run to the patrolling Daemon, and just around the corner opposite the gate you’ve opened is a second Daemon, farm these using your Omnicube to warp back to the Breach to respawn the Daemons until you have 10 fragments. Return to Arisen Dominion, enter the monolith, and speak to Nemundis for your reward and achievement.

One small step
Repair the EVA suit and walk in space.


For this achievement, you have to first find the Broken EVA suit armor set. This is located inside a hidden area inside the Embassy, just before you fight the Archon Slayer. In the Embassy hall leading to the Archon Slayer boss fight, run to the opposite end of the hall to a gate that you may have opened, that leads back to the beginning of the game. To the left of this gate in the hall is a hidden wall, which looks like 3 rectangles, press X on controller to interact with the middle wall and open it. Follow the path down a few floors, fighting Flying Fish and Tool Victims as you go, and once you reach the bottom floor, you’ll find a door that leads out into space. Once you get inside and activate the air lock, you’ll begin taking Radiation damage and oxygen damage, so you must go quickly. Follow the path in space outside to the corner, and turn right, you’ll find the Broken EVA set. Next, you’ll need to find the Model: EVA blueprints to repair the set, this can be found in Arcology Underside. From the first Breach in Arcology underside, turn left, and you’ll find it at the end of the gallery. Return to the Observatory, and craft the EVA set, then return to where you found the broken EVA set in the Embassy and go outside wearing it, you should get this achievement.

Master of Puppets
Kill Ozyormy Goija, the Master of Puppets.


This is the cosmic God found within Port Issoudun. His name is also a reference to Ozzy Osbourne, Gojira, and Metallica!

Undisturbed
Kill Undisturbed Defas Nemundis.


This is the cosmic God found within the Arisen Dominion.

Ashen Born
Kill Uthos, the Ashen Born.


This is the cosmic God found within Alma Mater. I loved this boss.

Consumer
Kill the Consumer.


This is a larger version of the consumer enemy. He can be found in Alma Mater Atrium just past the first Breach by Union Park.

Hostess
Kill Our Preying Hostess.


This is a larger version of the blade-thespian. She can be found at the top of Union Park in Alma Mater Atrium inside the large library.

Transporter
Kill the Transporter.


This is a larger version of the transporter. It can be found within the Arcology Underside. Good time to use that EVA suit!

For your thoughts
Find 66 coins.


For this achievement, you can cheat the system. I’ll link my very mediocre guide here that I’ve already created, or possibly try to create a better one, I’m sure you’ll all know which I put when this comes out:

My very subpar reddit guide:
https://www.reddit.com/r/Hellpoint/comments/i6gqxk/brief_somewhat_lowbudget_guide_to_for_your/

A better version, created by Rubhen925:
https://www.youtube.com/watch?v=A9h0PQ2jpik

I’m full of bad ideas!
Help the Architect repair the interface.


For this achievement, you must complete the Architects Questline. In order to do so, you must first speak to the Architect just past the Arisen Congregators in 1. Sohn District, he can be found inside the room here with the Central Breach. Speak to him and exhaust his dialogue.
Proceed to 2. Port Issoudun and defeat Ozyormy, and travel back to the Observatory. Here, he will be near the Breach, speak to him, and agree to help him. He will tell you a code to the power for the High Ateliers and Model: A.I Patch Conductor. To restore the power, head to Port Issoudun, and inside the dark room with the broken purple glowing bridge, head down the slope at the end of the room. Follow this path to the bottom to find a control panel, and input the code 72501. Next, you’ll need to find the parts to the A.I Patch Conductor.
The Nervous Wiring can be found just before you fight the Transporter in Arcology Underside. It’s at the bottom of the building with the platforms that lead up to him.
The Pulse Mineral is found inside the Arisen Dominion. Take the Elevator down to the Mausoleum, and head down to the very bottom, where you can find giant blue pools of radiation. Along one of these pathways, near the Breach located here, you can find it under the pathway, on a small ledge of rock.
The Alumina can be found at Alma Mater Atrium. Just past the Consumer boss fight, go straight, and at the cliff, there is a door on the left side. Head inside, go up the elevator, and it should be in this room. You should now have all you need to craft the A.I Patch Conductor. Head back to the Observatory, craft the patch now, and speak to the Architect. Give him everything, and he’ll say he will be waiting for you. At the end of the game, just before you fight The Author, he will be directly to the left of the button that opens the Authors room. Speak to him, and to finish, kill the Author.
This Questline is necessary for the Shattered Mirror achievement.

Galaxy’s Child
Help the Old Man.


For this Quest, all you have to do is speak to the Old Man at each of his locations. I’ll list each of the, in order.
1. Alma Mater Atrium: You can find him sitting next to his fire just outside the Union Park Breach, inside the park, on the left. Exhaust his dialogue. He will move to 2. Observatory:
From the Observatory Breach, head to the 2nd floor, left side. He will be inside one of the rooms on this floor at his fire. Exhaust his dialogue, and he will move to 3. Port Issoudun:
At the entrance of Port Issoudun, take the Exo-Lift next to the tram to a platform below. He will be down here, exhaust his dialogue, and he’ll move to 4. Arisen Dominion:
From the Grand Gallery Breach, go to the right across the non-broken bridge. Follow the path, killing a celestial beast, and congregators, until you are outside, on the edge of the pyramid. Take the left path, and jump up the side of the pyramid. Once you reach solid ground aground, you should see him just ahead at his fire. Exhaust his dialogue, and he will move to his final point, 5. Alma Mater Atrium:
Head back to the Union Park Breach again, and go to where you fought the Hostess inside the Athaneum (The Library at the top of Union Park). He is located directly above the Breach that is inside the library, proceed to him, exhaust his dialogue, enjoy the cutscene.

Shattered Mirror
Destroy the Prodigal Spawn.


To start this quest, you will meet the Prodigal Spawn at 1. the Arisen Dominion. Above the Grand Gallery Breach, once you have activated the Exo-Lifts that are next to the Breach, climb the Exo-Lift, and head straight through the door here. Take the hallway to the left, and you should find him. Exhaust his dialogue, he will move to 2. Port Issoudun. (He will move after you have killed Undisturbed Defas Nemundis)
Here, he will be in the same location as the Old man, below the tram at the bottom of the Exo-Lift. Speak to him, and agree to help him, he will open the door here for you. Go this way, reach the end of the area and pick up the Red Loot Cube to get the Model: Heir of Chaos.
Now, you’ll have to craft this. The Black Tempering can be found at Port Issoudun. From the tram at the beginning, enter the door to go inside. Climb down the Exo-Lift, reach the end of this short hallway, and fall slightly down into the rectangular lower section of this room. Ride the Exo-Lift up to the small room above, the Black Tempering is here. This is directly below the Silo Breach.
Next, the Organic Fiber is found inside the vault that leads to Ozyormy in Port Issoudun. Last, the Beating Heart can be found at the Arisen Dominion. It is on the 2nd level of the room with the Giant Blue Sun, along with an Occult Crafting Station in one of the corners. Now, head to 3. Alma Mater.
At the elevator that leads to Uthos, the Ashen Born, turn around, and at the opposite far end of the room is a set of stairs leading up. Climb these, and he will be here waiting. Craft the Heir of Chaos at the Occult Station here, and give it to him. He will leave. To finish this achievement, you must Do the Architects Quest and Kill the Author, this will take you to the true final boss of the game. Finish this fight, and the achievement is done.

Well of Souls
Input one of the Five Eyes Codes.


For this achievement, I’ll have you input two sets of codes, specifically for the next achievement. Once you have activated Eye Tower Two. This can be done from the Arcology Underside area. At the very end of Arcology Underside is a door that will take you to Alma Mater Atrium. Go here, and once here, pick up the Golden Loot Cube to get the Eye Two Tower Key. Ride the elevator here up, and go to the room located behind the tower. Activate Eye Tower Two. Now you’re ready to go input the codes. Head to Arcology, where you fought the Celestial Beast, and from the Breach here, enter and ride the elevator to floor three. Input the code 2602 9417 to Eye Two, and 5624 7947 to Eye Four.

---After rereading this, it may be unclear. To activate the elevator that leads to where you actually input Eye Tower Codes, you must go to Sohn District, where you first meet the Architect just past the Arisen Congregators boss room. Approach the tram that leads to Port Issoudun, but don't use it. Instead, head to the left. Follow this path to the end and you can activate the elevator necessary.

Knights
Slay the Four Archon Knights.


The First Archon Knight requires the use of the Eye Towers, done in the previous achievement. Once done, you’ll have to wait for the Black Hole Hour to start (where your orange circle overlaps with the gray circle). During the Black Hole Hour, head to Sohn District, and go to the Arisen Congregators boss room. Inside the room looking towards the three paths that enter it, take the left path, and follow it to the end. You should come to the Hell Door, which is where the First Archon Knight is.
The Second Archon Knight is located at the Alma Mater Atrium. Go to the elevator inside Eye Tower Two that we activated, and ride it up to the top floor. Follow this path to the end to fight the 2nd Archon Knight.
The Third Archon Knight is located in Alma Mater Atrium. From the Union Park Breach, enter the Park, and go towards the far back-left corner staircase that would lead you to the Library. Near this staircase is a staircase that goes down underground. Head down here, and find the monolith inside. Enter the underworld, and head back outside into Union Park again. From here, turn 90 degrees to the right and run straight, you’ll come to a pit with a cave at the end. This will have a purple boss wall, enter it, and the Third Archon Knight is here.
The Fourth Archon Knight is located at the Arisen Dominion. At the very bottom of the Arisen Dominion, near the Pulse Mineral found in the achievement for the Architect above, there are multiple pools of blue radiation. Here, you’ll notice a Radiation Waterfall, behind it is a path that leads to the Patriarch and a monolith. Enter the monolith. Once inside the underworld, leave the monolith, and when leaving, go to the right of the water and jump out of the radiation. Behind a rock here is an Exo-Lift, climb this. Climb the stairs here, and go left. Follow this until you reach a room that can go left or right, go through the door on the right (near the purple wall). Go down the steps, and follow this path to the end. The Fourth Archon Knight is here. That should now be all four Archon Knights.

Good Spawn
Do as the Author asks.


Surrender your data to the Author. This ends the game.

Interface
Kill the Interface.


Keep your data, and kill the Author.

Sentient
Kill the Sentient.


This is the boss of the True ending. If you did the Prodigal Spawn quest, he will also fight you alongside this boss.

To the Fringe
Reach a more challenging parallel universe.


Beat the game and reach NG+.

My old friend
Turned off the lights, from start to end.


I am not sure what completes this achievement. EDIT: The way I got this achievement was to go into NG+, and not use my Omnicube or save and quit my game. Go straight to the Archon Slayer, and then the Author and kill him. This should get you the achievement. I've read this achievement could have to do with beating the game in one shot (no save and quit), never using your Omnicube light, and turning off the light settings in game, but the bolded text above was what actually got me this achievement. I never touched my settings.