Abyss of Neptune is an impressive free underwater survival horror game set in the deep seas of the Bermuda Triangle. It should generally take about 30-45 mins to complete.

This guide provides both a full playthrough guide video and text descriptions for all achievements. Each description (where possible) will also include a timestamp link to the video if you need any further help.

Note: The achievements here are in the order in which you should obtain them.

Note 2: In the recent v1.0 update, the developers have added a new achievement - Abyss of Masochism


Timestamps
0:00 Intro
2:35 Log 1
3:00 Abyss of Learning
5:08 Log 2
5:30 Gameplay
7:20 Abyss of Shooting
7:30 Gameplay
8:50 Log 3
9:22 Gameplay
11:06 Log 4
11:24 Gameplay
12:06 Log 5
12:24 Gameplay
14:54 Log 6
15:32 Gameplay
22:12 Log 7
22:56 Gameplay
25:56 Log 8
26:22 Gameplay
31:18 Log 9
31:48 Gameplay
34:16 Abyss of Academia
35:02 Log 10
35:20 Level Boss Gameplay
42:30 Abyss of Developers (Secret Developer Room)

Abyss of Learning
Complete the tutorial.


This is story related and will be unlocked as soon as you enter the first hallway.

Abyss of Shooting
Get the harpoon gun.
Video guide timestamp link (7:22)

This is considered story based and is obtained by progressing through the game. However for reference, it'll be on a table in the Kitchen.

Abyss of Searching
Find 3 logs.


See below under Abyss of Completion for a full set of locations. However, you should easily find 3 before leaving the first area of the game.

Abyss of Exploration
Find 6 logs.


See below under Abyss of Completion for a full set of locations. However, you should have 6 logs before leaving the second area of the game.

Abyss of Academia
Complete the Academics Wing.
Video guide timestamp link (34:18)


Story based and will be unlocked as you progress through the game and enter the final area.

You need to gather 3 diaries from each of the archive rooms located around the statue. This will unlock when you collect all 3 and insert them into the pedestal in front of the statue located at the entrance. Doing so will reveal a hidden elevator underneath the statue.

Abyss of Completion
Find all logs and complete the game.


There a total of 10 Logs to find throughout the game.

Log 1: "IT'S KILLING US"
Video timestamp: 2:38
Location: Access Hallway - Near the beginning of the game, you'll eventually come to a stairway that leads you into the main compound. Under this stairway is the first log.


Log 2: "The Reefs Are Back"
Video timestamp: 5:12
Location: Cafeteria - In the far corner on the floor against a set of unturned tables.


Log 3: "WE DID IT!"
Video timestamp: 9:06
Location: F Showers - Travel through the air duct in the ceiling from the M Dorms room. The log is on the floor in the cubical with an open door.


Log 4: "Neptune"
Video timestamp: 11:10
Location: Lobby - In the middle of room hidden amongst a pile of chairs and tables.


Log 5: "Failed Rituals"
Video timestamp: 12:10
Location: Librarian's Office - Hidden to the right of doorway as you enter.


Log 6: "I know what we're missing"
Video timestamp: 14:56
Location: Control Room - Against a table locked inside a safe. Use your key to unlock.


Log 7: "We're Close"
Video timestamp: 22:40
Location: Hallway (1F) - Enter the duct from Hallway (2F) and follow it through all the way to the exit at Hallway (1F). The log is at the very end of this tunnel next to a medkit.


Log 8: "The f**k are you doing down there?"
Video timestamp: 26:00
Location: Atrium (1F) - Sitting in an open part of the plant life on the very top platform of this circular room.


Log 9: "Adam"
Video timestamp: 31:36
Location: Historical Records - As you enter, stay to the righthand side of the room and follow it all the way to the back of the room. The log will be at the very end where it becomes blocked underneath a "G - Z" sign.


Log 10: "I'm so tired"
Video timestamp: 35:10
Location: Intersection - After taking the elevator down, find the duct entrance on the floor in this room. The log and medkit should be visible as soon as you enter.



NOTE: The achievement will only unlock once you complete the game.

Abyss of Grit
Complete the game without using any healing items.


Not as difficult as you may think as long as you're careful to dodge, run and shoot when necessary.

Some general hints...

• Ammo is limited so only take out enemies where required.
  
• Try to go around the large enemy. Tease him into open areas and/or go around him.
  
• You can generally take 4 hits from enemies which ultimately means you have 4 lives to play with.
  
• Remember you can retrieve any misfired harpoons.
  
• Save and refill your oxygen whenever you can as this creates a checkpoint.
  
• If worst to comes to worst, simply die and retry from a checkpoint. This does not affect this achievement.

Abyss of Speedrunning
Complete the game in under 30 minutes.


Again, not overly difficult once you know the layout of the map and object placement. Obviously use the Jet as much as possible and only refill your oxygen when absolutely necessary. You get more time than you think here, even when it starts to signal its low.

The only real annoyance/issue is in the latter half of the game when the larger creature spawns randomly. This can cause you to get side tracked especially when he spawns in a one way corridor, eating into precious time.

Abyss of Mercy
Complete the game in easy mode.


Nothing more to add as the title says it all really :)

NOTE: This achievement will unlock if you complete the game on normal mode.

Abyss of Persistence
Complete the game in normal mode.


As above.

NOTE: This achievement will unlock if you complete the game on hard mode.

Abyss of Masochism
Complete the game in Hard Mode


Same as the previous completion based achievements.

Abyss of Developers
Find the hidden room.
Video guide timestamp link (42:30)

You can only reach this hidden room once you've taken the elevator down to the last part of the game, before you take on the final boss. In this room you will find a locked safe which will contain a 10V battery to help you unlock this achievement.



At numerous times throughout the game you have encountered rooms that hold a counter where you can swap these batteries to unlock various sections of the map. The hidden room can only be entered from the Kitchen which is at the beginning of the game! So yeah, we need to head all the way back and swap out a batteries along with way.

So once you've retrieved the battery, head back up the elevator and towards the Control Room. Ensure you have 15V active on this counter before moving on.



Now head back to the Kitchen and ensure you have 20V active on this counter to unlock the Air Flow in the duct behind you on the floor.



Now enter the duct which you should now be able to navigate freely. Travel all the way to the end to finally get to the secret developer room.