Fathom
Free · play online in your browser, no download
An idle deep-sea salvage game: your sub dives a trench on its own, and a Leviathan guards every border.
Official site joebi1.itch.io, verified Nov 3, 2026. Linked from the developer's own Reddit post on r/incremental_games.
Where to play
Every platform this game is on. Links are checked against official sources; we never host or mirror games.
- Play free — itch.ioitch.ioEarly access · Early development build (In development on itch.io); v0.4.0 when announcedFree
Plays in the browser on itch.io. No download.
Browser (no download) · Mobile · Official link verified Nov 3, 2026.
About Fathom
A free idle game in the browser, built for phones as well as desktop. Your submarine dives on its own, cuts scrap from wrecks down a trench wall, surfaces and unloads; you refine the scrap into alloys, upgrade the hull, air and hold, and push deeper, and holding the screen makes the sub work faster while you watch. Each border is guarded by a Leviathan you have to out-build, the first being the Reef Eel. Deeper down there are wrecks with stories, skills, fishing, drones and stations to prestige from, and a guided chain of goals takes new players to the first Leviathan in about fifteen minutes. The sub's plating, fins and armour change as you upgrade, and the lamp on its mast shows your air. Progress saves in the browser and backs up to the cloud under a restore code, so a run can continue on another device; anonymous play statistics can be turned off in Options. The developer, Joebi1, says Fathom is built “with a lot of help from Claude”, which wrote most of the code, while the design, direction, playtesting and every decision are the developer's. Made with Godot. No ads; the developer says a premium currency is planned but no payments exist yet.
How it was built
Partially verifiedThe developer's post on r/incremental_games (9 Oct 2026, UTC) ends with an AI disclosure: “Fathom is built with a lot of help from Claude. It wrote most of the code. The game design, direction, playtesting and every decision are mine.” The developer does not say whether this was Claude Code or the Claude app, or which model.
- Developeritch.io AI disclosure: AI Assisted. The page lists Godot as the engine. — itch.io
Built in Godot as an HTML5 build for itch.io, with Claude writing most of the code and the developer doing the design, direction and playtesting. The page says the build updates automatically as the game grows; saves are kept in the browser, with a cloud backup under a restore code, and anonymous play statistics (goals reached and errors, under a random id) help find where players get stuck. Who made the pixel art is not stated. No AI runs in the game.
- Engine / framework
- Godot
- Languages
- Not disclosed
- Team size
- Not disclosed
- Initial build time
- Not disclosed
- Development time
- Not disclosed
- Development cost
- Not disclosed
- AI-written code
- Not disclosed
“Fathom is built with a lot of help from Claude. It wrote most of the code. The game design, direction, playtesting and every decision are mine.”Verification notes: AI use from the developer's post by u/Business_Journalist4 on r/incremental_games (9 Oct 2026, 13:06 UTC) and the developer's replies under it, read from the Arctic Shift Reddit archive on 8 Nov 2026; the post links the itch.io page. Gameplay, saving, statistics and the AI disclosure (AI Assisted only) from the itch.io page, re-read on 8 Nov 2026; the itch.io field is not code evidence on its own, the developer's statement is. “Most of the code” is the developer's phrase, so no share is recorded. Developer: the itch.io account Joebi1, posting on Reddit as Business_Journalist4 in the first person; no name, team size or location is given. In replies the developer says the game had not been tested on Android when it was posted, that holding is an optional 50% speed boost, that the game will stay free with no ad breaks and a premium currency that is easy to earn in the midgame, and that no payments exist yet. The itch.io page shows no publish date (last updated 24 Oct 2026, 00:23 UTC); the Reddit post of 9 Oct 2026 is the first dated public mention. The web build is a Godot export; its scripts were not inspected for network calls beyond what the page describes. The game was not played.
Development history
The developer shares version 0.4.0 on r/incremental_games, saying Claude wrote most of the code.
DeveloperReddit (u/Business_Journalist4)Latest update of the itch.io page as fetched on 8 Nov 2026.
Observeditch.io
Game performance
Each figure measures something different — concurrent players, owners, downloads and sales are never interchangeable and are never added together. Labels show where each number comes from.
itch.io
Free in the browser (HTML5) with mouse or touch; no ads. The developer says a premium currency is planned to speed progress, but no payments were available when it was announced.
Not publicly available: Gross revenue.
Sales & revenue (all platforms)
Browser game — there are no downloads to count.
Reviews & rankings
Not yet reviewed by our editors.
Sources
| Source | Type | Published | Accessed |
|---|---|---|---|
| Fathom: an idle deep-sea salvage game where your sub dives a trench and Leviathans guard each border (browser, mobile, no ads) (r/incremental_games) Reddit (u/Business_Journalist4) | Social post | Oct 9, 2026 | Nov 3, 2026 |
| Fathom by Joebi1 itch.io | Store page | Not confirmed | Nov 3, 2026 |
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