THAT SINKING FEELING is a trifold adventure made for Triptech Game Jam 2025 compatible with the Mothership Sci-fi Horror RPG. 

Your crew will onboard the Manta-61 submarine and dive into the ocean of Proteus V in search of a sunken freighter. 

The adventure can be run as a one-shot for 3-5 players. The theme of the game jam was Beneath the Surface, expressed through the submarine dive. But also through the mysterious cause of the signal, and your crew who might be more than what they seem. 

• A three-phase adventure. The descent, an investigation into the sunken freighter, and finally a desperate ascent back up to the surface.
• Four NPC companions to accompany your crew through the adventure.
• The Manta-61 submarine which can be used for your own nautical adventures.

Trigger Warnings: Mind control, alcohol use, thalassophobia, deep sea horror, claustrophobia, necromancy.

This work is AI-Free. It does not include content or media that was AI or Machine Generated. Supporting this work means supporting real people.

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Credits:

Writing and Layout by Olen of olenthings.itch.io

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Color palette by Yelta on lospec.com / 1bityelta.itch.io

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Icons by Delapouite &  Lorc, of game-icons.net under the CC BY 3.0 

Delapouite

• https://game-icons.net/1x1/delapouite/planet-core.html
• https://game-icons.net/1x1/delapouite/three-friends.html
• https://game-icons.net/1x1/delapouite/shark-fin.html
• https://game-icons.net/1x1/delapouite/checklist.html

Lorc

• https://game-icons.net/1x1/lorc/wolf-trap.html

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Royalty free images by courtesy of unsplash.com

 Daniel Sinoca

https://unsplash.com/photos/a-large-body-of-water-that-is-under-water-7BLc53z03r...

Zachary Theodore

https://unsplash.com/photos/oil-rig-guADzpF9pDI

Matheus Frade

https://images.unsplash.com/photo-1568823573780-d83ed62bcda5