Cthulhu: The Cosmic Abyss Trophy Guide
Welcome to our Cthulhu: The Cosmic Abyss Trophy Guide, where you can find everything you need to 100% the game.
Summary
- Estimated Time to Platinum: 7-10 Hours - Could be longer without a guide since you will have to find and read a lot of clues.
- Difficulty: 1/10 - No combat, just finding and reading clues to solve puzzles.
- Missable Trophies: 18 - Everything that is not story-related. While the game does feature chapter select, using it will reset your save to that chapter. Additionally, trophy and collectible counters can be unreliable when using chapter select.
- Playthroughs Needed: 1
Intro
Cthulhu: The Cosmic Abyss is a Lovecraftian thriller where you play as an investigator. The game features no combat and instead focuses on exploring semi open areas, gathering clues, and solving puzzles to progress through investigations.
It also includes a corruption system that changes based on how you approach each investigation. Your corruption level determines which ending you receive.
Luckily, all trophies including the only trophy related ending are tied to the low corruption path, meaning you can unlock every trophy in a single playthrough.
Alongside a few miscellaneous trophies, there are also 19 collectibles required for trophies. It is recommended to follow our 100% Walkthrough to avoid missing anything.
Step 1. 100% Playthrough
Follow our 100% Walkthrough. This guide will take you through full completion of Cthulhu: The Cosmic Abyss, covering progression, puzzle solutions, how to achieve the lowest corruption outcome in every investigation, and the locations of all collectibles.
By following this guide, you will unlock every trophy.
Before starting, there are a few important things to know.
Cthulhu: The Cosmic Abyss features a corruption system that changes depending on how you solve the game’s main cases, known as investigations. Each investigation can be completed in two different ways, and most chapters include one, although some do not. To earn the Mens Sana trophy, you must reach the end of the game without exceeding the corruption threshold. This requirement is fairly lenient and does not require a perfect run. However, each investigation also has a trophy tied to achieving the low corruption outcome, so it is strongly recommended to follow the guide and aim for the low corruption result every time. If you make a mistake, you can replay chapters, but doing so will reset your progress back to that point.
There are six possible endings based on your corruption level, but only one is required for the Platinum. This is the route covered in the walkthrough.
Difficulty settings do not affect trophies, so it is recommended to enable all assists except Free Clue Analysis. Keeping this option disabled ensures that analyzing clues consumes energy, which is necessary for using orange Lichen to restore energy and earn the Addicted trophy by consuming it ten times. Once you have unlocked the trophy, you can enable the setting if you prefer. You can also temporarily enable it if you run out of energy and have no Lichen available, as analyzing clues without energy will increase corruption and may push you away from the optimal ending.
You will also need to solve 15 deductions to unlock the Elementary trophy. Certain items you examine or analyze will appear in the Vault menu as deductions, where you must link them with other clues to solve them. These are not required to progress through the game if you already know the puzzle solutions. However, the walkthrough covers 15 deductions for the trophy, although there are many more available throughout the game.
All collectibles are included as well.
15 Evolutions required for the Augmented Agent trophy
4 Energy Upgrades required for the Full Charge trophy
9 Evolution Slot upgrades which are not tied to any trophy
In addition, make sure to analyze any clues you come across. You will need to analyze 25 clues and 10 sub clues for trophies, but this should come naturally as there are far more than required throughout the game.
Trophy Guide
Unlock all trophies.
Obtained after unlocking every other trophy.
Find Mei in the Other World,
Unmissable. Story-related. Obtained at the end of Chapter 1.
Cross the maze.
Unmissable. Story-related. Obtained at the end of Chapter 2.
Escape from the deep one.
Unmissable. Story-related. Obtained at the end of Chapter 3.
Leave the Other World.
Unmissable. Story-related. Obtained at the end of Chapter 4.
Get the Star of Shamash,
Unmissable. Story-related. Obtained at the end of Chapter 5.
Reach the prison.
Unmissable. Story-related. Obtained at the end of Chapter 6.
Replace the watcher.
Unmissable. Story-related. Obtained by finishing the game.
Cross the maze without reassembling the cursed totem.
Obtained by successfully solving the investigation in Chapter 2 with the low corruption outcome. This requirement is fully covered in our100% Walkthroughguide.
Restore the seal and destroy the deep one.
Obtained by successfully solving the investigation in Chapter 3 with the low corruption outcome. This requirement is fully covered in our100% Walkthroughguide.
Reach the star without killing the guardian.
Obtained by successfully solving the investigation in Chapter 5 with the low corruption outcome. This requirement is fully covered in our100% Walkthroughguide.
Open the door without letting the matter spill out.
Obtained by successfully solving the investigation in Chapter 6 with the low corruption outcome. This requirement is fully covered in our100% Walkthroughguide.
Finish the game without exceeding the corruption threshold.
Get to the end of the game without filling the corruption gauge. This is achieved by solving as many investigations as possible with the low corruption outcome. The game is lenient, so you don’t need to obtain the low corruption outcome in every single investigation. However, we still recommend aiming for it each time to also unlock the investigation-specific trophies tied to these outcomes. All low corruption outcomes are fully covered in our100% Walkthroughguide.
Find all evolutions.
Evolutions are collectible passive perks that provide helpful bonuses throughout the game. There are 15 in total, and all are missable.All Collectiblesguide.
Find all energy upgrades.
Energy Upgrades will give you more energy slots. There are a total of 4, and they are all missable.All Collectiblesguide.
Analyze 25 clues
Obtained by analyzing 25 clues. This will almost certainly come naturally during your playthrough. You can analyze a clue by pressing the large orange “Analyze” button while examining certain items. There are far more than 25 clues throughout the game, and they provide key information needed to solve puzzles and investigations.
Solve 15 deductions.
Some items you examine and analyze will be saved in the Vault menu as Deductions (purple clues). To solve a Deduction, you must find the correct matching clue and drag it onto the original clue. There are far more than 15 of these in the game. We cover 15 in our100% Walkthroughguide.
Find 10 sub-clues by inspecting objects.
Obtained by analyzing 10 sub-clues. This will almost certainly come naturally during your playthrough. You can analyze a clue by pressing the large orange “Analyze” button while examining certain items. Some of these will count as sub-clues. There are far more than 10 throughout the game, and they provide key information needed to solve puzzles and investigations.
Use 10 doses of Lichen.
Lichen are orange, mushroom-like plants found throughout the game. They can be consumed to restore energy, which is used to analyze items and clues. For this reason, it is recommended to keep the “Free Clue Analysis” difficulty option disabled, as analyzing clues must consume energy in order to use Lichen and progress toward the Addicted trophy, which is earned by consuming it ten times. Once the trophy is unlocked, you can enable this setting if you prefer. You can also temporarily enable it if you run out of energy and have no Lichen available, as analyzing clues without energy increases corruption and may push you away from the optimal ending.
Reveal 25 different clues using sonar frequencies.
Analyzing certain items allows you to unlock new frequencies in the Sonar menu. You can equip these and press to scan for items related to that frequency. You will use this frequently throughout your playthrough, so it should come naturally.
Reconstruct Mei's drawing.
Obtained by solving the Drawing puzzle in Chapter 1. This is the large circle on the wall and is hard to miss. To solve it, collect the five pieces of paper in the same room that contain parts of the drawing. Three are on the floor in front of the circle, and the other two are on the table to the left, with one requiring you to examine it and flip it over. Once you have all five pieces, place them on the circle on the wall in the correct positions.
Reactivate the PIT station.
Once you reach the station in Chapter 2, you will need to find and place two hydrogen canisters, then turn on the generator. After that, return to the upper area of the Control Module and press the green button.
Translate the temple inscriptions.
During Chapter 3, you will come across an NPC tied to a rock, which is where the investigation begins. Go down the stairs behind him all the way to the tent at the bottom. Inside, open the crate and pick up the powered battery. Then return to the NPC and look to your right for a PC on a crate next to a stone tablet. Remove the broken battery and insert the powered one, then analyze the PC. After that, examine the stone tablet. Finally, enter the Vault menu and connect the stone tablet with the PC clue to solve the deduction and unlock the trophy.
Translate the language of the great race of Yith.
During Chapter 5, head left once you reach the large creature in the center, where the title screen appears. Here you will find a broken stone tablet. Pick it up to start a deduction. Then cross the invisible bridge on your left and continue along this path until you reach the laboratory. Inside, move around the bottom floor and loop back to your left to find the other half of the tablet on a round structure on the floor. Then combine both pieces in the Vault menu to complete the deduction and unlock the trophy.
Using sonar, reveal the invisible tentacles of the citadel's guardian.
During Chapter 5, head left once you reach the large creature in the center, where the title screen appears. From here, go left again, cross the invisible bridge, and continue along this path until you reach the laboratory. Inside, you will need to examine and analyze three items. The first is Macroplankton, found on the floor to your left as soon as you enter. The second is Human Blood, located in the lower area just to the right of the Macroplankton. The final item is the Shoggoth Heart, found inside a broken crystal sphere on the wall on the right side of the lower floor. Once all three have been examined and analyzed, open the Sonar menu and activate the three new frequencies. Using the sonar with all three equipped will reveal invisible tentacles and unlock the trophy.
Teleport using the Star of Shamash.
During Chapter 6, you will need to engrave symbols into the star (cube). In the same room where you engrave the symbols, or any of the small rooms, place the star on the small pedestal on the side of the room with the I symbol facing you. Then look at it for a few seconds until it begins to glow. As soon as it does, pick it up to be transported to a secret room and unlock the trophy.
Unlock a yith mechanism using sonar.
In the main circular area in Chapter 6, interact with and analyze the pillars around the area. One of them will grant you the Ultrasonic Stone Frequency. Then go down the stairs on the side of the area to find a locked door at the bottom. Open it using the Ultrasonic Stone Frequency to unlock the trophy.
Prevent Cthulhu from awakening.
This is the only trophy tied to an ending. To obtain it, you must finish the game below the corruption threshold. At the very end, when aiming the stake, choose to destroy the star (cube). This is the ending we cover in our100% Walkthroughguide.
