We Traced Tunnelborn Back to Flarebound. Then the Build Files Raised New AI Questions

What We Found in the Build Files

Our comparison of the Flarebound and Tunnelborn demos found shared project data, identifiers and retained assets. A separate AI-disclosure trail raises questions about what changed between the two projects — and what happened to the assets originally disclosed as AI-assisted.

What started as a question about the artwork in Tunnelborn turned into something much more concrete: an earlier game called Flarebound, two Steam demo builds, old project material still inside Tunnelborn, and an AI-disclosure trail that is no longer straightforward to see.

Our team first noticed elements in the Tunnelborn artwork that raised questions about possible AI use. That was a reason to look closer, not evidence by itself. So we did not start by calling the artwork AI-generated. We followed the project instead.

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We traced Tunnelborn back to Flarebound

That trail led to Flarebound, an earlier project associated with the 42 BYTES name. We downloaded the Flarebound Demo and Tunnelborn Demo from Steam and carried out a read-only comparison of the installed builds.

The result is stronger than a visual resemblance. The examined Tunnelborn build contains project-specific material carrying the Flarebound name and identity.

• Two Flarebound-named gameplay data files are byte-identical between the builds.
• A third 4,178-byte Flarebound data file differs by only one byte.
• Both builds retain the same serialized Unity productGUID.
• Tunnelborn still contains Flarebound.Data and implementation names including OnClickWishlistFlarebound and OnClickShareFlarebound.
• Our defined raw-byte search found 52 case-insensitive occurrences of “Flarebound” across eight Tunnelborn files.
• An old Flarebound logo payload remains packaged inside Tunnelborn and is byte-for-byte identical to the corresponding payload in Flarebound.

That does not mean Tunnelborn is simply a byte-for-byte renamed copy. Major build files differ, the games report different company and product names, and they were compiled with different Unity versions. Nor can installed builds reconstruct the developer’s source-control history.

The narrower conclusion is the one we can support: the examined Tunnelborn build carries substantial project-specific material forward from Flarebound.

Then the AI disclosure became relevant

Flarebound’s Steam listing carries an AI Generated Content Disclosure stating:

“As a single indie developer I had to use AI to help with creating some of the assets for store pages and logos.”

That wording is important. It says AI was used to help with some store-page assets and logos. It does not establish that Flarebound’s code, all of its artwork, or the Tunnelborn artwork that first caught our attention was generated with AI.

But once the build comparison established strong Flarebound-to-Tunnelborn continuity, an obvious question followed: what happened to the AI-assisted material during the transition?

Tunnelborn also has an AI-disclosure trail

SteamDB records AI Content Type 1 for Tunnelborn, App ID 4829290, while the Tunnelborn Demo, App ID 4933340, also has an AI-content metadata trail.

During our reporting on September 27, targeted Bing searches surfaced Steam-indexed material associating the Tunnelborn Demo with the same disclosure wording used by Flarebound. We preserved those results. On October 1, targeted Google results continued to associate the exact wording with Tunnelborn Demo and cited Steam as a source.

Readers can try the same targeted search in Bing or Google:

site:store.steampowered.com/app/4933340 "As a single indie developer I had to use AI"

Search indexes are dynamic. Results can disappear, change after a recrawl, or reflect older versions of a page. For that reason, we treat these searches as evidence of an indexed disclosure trail, not as proof of what the current live Steam page displays at any given moment.

When we checked the current Tunnelborn storefront presentation, the equivalent disclosure was not consistently visible. We do not know from the public evidence alone whether AI-assisted assets were replaced, whether the disclosure information was updated, whether Steam’s presentation changed, or some combination of those things.

That is the part we wanted the developer to explain.

Who is behind the project?

The public developer history also connects the names involved. Marc Grabow’s public GitHub profile identifies him with 42 BYTES. Estonia’s official business register lists Grabow as the board member and sole shareholder of CROCFISH OÜ.

There is also a public bridge through MOK: Super Space Taxi: its itch.io listing identifies 42 BYTES as the author, while its Steam listing identifies CROCFISH as developer and publisher.

We asked for an explanation

Fix Gaming Channel originally received access to Tunnelborn through WASD Games, which supplied a Steam key for coverage. In our initial correspondence with WASD Games, a representative told Fix Gaming Channel that, “as far as I know,” AI could be excluded from Tunnelborn’s Steam capsule images, promotional materials, cutscenes, writing, audio and marketing assets. The same response stressed that this still needed to be confirmed with the developer and did not rule out possible AI use in pixel art or character and creature artwork.

That initial understanding does not neatly match the historical/indexed Steam trail we subsequently found, which associates Tunnelborn with a disclosure stating that AI was used to help create some assets for store pages and logos. WASD later clarified that it had been hired to secure coverage and did not develop or publish Tunnelborn. We therefore regard the discrepancy as a question for the developer, not an allegation against WASD.

The original coverage email from WASD also included Tunnelborn promotional artwork. We have not established that this specific image was AI-generated or AI-assisted. Its relevance is simply that it formed part of the promotional material we received while trying to clarify the project’s AI use.

We asked Grabow/CROCFISH about the relationship between Flarebound and Tunnelborn, what the original AI disclosure covered, whether any AI-assisted assets carried forward, whether those assets were replaced, and why the disclosure situation changed.

WASD told us the developer was away on holiday for approximately a week. Fix Gaming Channel also contacted Grabow directly and offered a right of reply. As of October 1, 2026, we have not received his response to those questions.

That silence is not evidence of wrongdoing, and we are not going to assign a motive to it.

So what do we actually know?

We know the examined Tunnelborn build carries substantial Flarebound project material forward. We know Flarebound disclosed AI assistance for some store-page assets and logos. We know Tunnelborn and its demo have an AI-content metadata and search-index trail that has been visible through SteamDB and search results.

What we do not yet know is which specific Flarebound assets were AI-assisted, whether any of those assets remain in Tunnelborn, whether they were replaced, or why the disclosure is no longer consistently visible in the current storefront presentation.

And we still cannot say that the particular Tunnelborn artwork that started this investigation was generated with AI.

That is where the story stands. Not “caught,” not “exposed,” and not a conclusion built from how an image looks. It is a documented project connection followed by a disclosure trail that leaves reasonable questions unanswered.

This story may be updated

Fix Gaming Channel will continue to follow this story. If CROCFISH or Marc Grabow responds, if the Steam disclosure changes again, or if new documentation clarifies what happened between Flarebound and Tunnelborn, we will review it and update or follow up on this reporting where appropriate.

If you are a developer, reader, industry source or anyone with relevant documentation, corrections or additional context about this story, you can contact us at contact@fixgamingchannel.com. We also welcome tips about other stories in the games industry. Please send material you can substantiate; confidential tips will be handled with appropriate care.

We will also follow this investigation with a broader explainer on what does and does not count as evidence of AI use in games.

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