The history of AI game mashups

How putting one game inside another went from two Rust rewrites to the biggest modding story of 2026 in about two weeks. Every entry is dated and sourced, and repository facts are re-checked (last on October 8, 2026).

1. Before the wave: rewrites

The mashup trend didn't start with a mashup. It started with rewrites. Through summer 2026, a few developers used AI coding agents to rebuild whole game runtimes in Rust on the Bevy engine, loading the original data from their own copies. benilla, a World of Warcraft 1.12 client, came first in July. By mid-September two more mattered: skate-3-rust-engine (8 September) and vladtrc's Modern Warfare 2 runtime IW4L (13 September).

On 19 September chasm, the skate engine's top contributor, posted a clip captioned along the lines of I rewrote Skate 3 in Rust. It's the earliest known viral post of the trend.

2. The model

On 22 September Anthropic released Claude Opus 5.5, about 40% cheaper to run than Opus 5. Nearly every mashup of the next fortnight credits it. Cheap, long agent sessions made it affordable to point a model at a game's compiled code for hours, which is the step every technique below depends on.

3. The first mashups

Because IW4L and the skate engine were both Rust/Bevy codebases, they could be merged. On 27 September chasm released the 2010 Rust Rewrite Mashup: MW2 multiplayer where pressing J drops you onto a board with Skate 3's physics, inside an endless Minecraft world from a third Rust engine. Three days later came SkyCraft, which took the opposite approach. Instead of rewriting anything, it runs Minecraft and Skyrim side by side and links them through shared memory. It's the passthrough mod, and it has the most downloads of anything here.

The same day, ER Mario used libsm64 to put Super Mario 64's real movement into Elden Ring (a library import), and Rehan Sheikh published universal-modder, a skill pack that lets an agent mod almost any game you own. It became the most-starred repository of the wave.

4. The viral week

Between 28 September and 5 October the clips outran the code. Minecraft in Elden Ring by Tobyn Jacobs became the trend's defining image (reported at 22.5 million views), and has never been released. Tarkov in Skyrim, P.E. Cooper's World at War Zombies in a browser and its crossovers, and later Elden Ring as an eight-game shooter followed, along with clips whose creators were never identified, like TNT in Red Dead Redemption 2. chasm's YouTube round-up, Modding has Changed FOREVER…, reached 2.4 million views in a week.

The clips with code were the minority. When VGTimes went through them one by one on 4 October, only a handful could actually be downloaded.

5. Forks, tools and ports

The released projects were forked almost immediately. SkyCraft's design was ported to Fallout 4 and Outer Wilds, and ArkWeb borrowed it to bring Spider-Man's web-swinging to Gotham. The skate engine went into Vice City and GTA III, Bully and San Andreas, the last of them also building on the MW2 mashup.

Tools followed the forks. On 5 October Melty, a Y Combinator-backed Windows launcher, offered one-click installs of mashups for games you own, with new ones written by coding agents. The same agents were producing full ports: Halo: Combat Evolved in a browser with 128-player rooms, and an AI-generated Banjo-Tooie recompilation.

6. The backlash

The counter-trend arrived within a week. On 2 October Kotaku asked modders to stop putting games inside other games, arguing the combined mechanics never actually interact. On 3 October the Mario in Elden Ring clip, at 2.9 million views, was taken down after a copyright claim. On 5 October VGC quoted modders calling the trend an "AI slop factory", and the human teams behind Zelda and Banjo Recompiled disowned the AI Banjo-Tooie port as a "slopcomp". Nexus Mods had already required AI disclosure since July, and no mashup appeared there.

The projects that held up were the ones with code you could read and builds you could run.

7. What came next

The best-received project of the second week wasn't a two-game clip. It was a careful rewrite: Funny-Bones' Elden Ring combat controller, rebuilt in Rust from the game's own timing data and shown running in Skyrim. It earned "holy peak" replies in the same week as the backlash.

Every mashup above needs the original games. The next step is mashups that don't: mechanics rebuilt from observation with original code and CC0 art, playable instantly in a browser. That's what this site makes. Play the clean-room tributes, or read how clean-room mashups work.

Family tree

What each mashup was built on, as credited in its own repository. A project built on several things appears under each of them.

Built alone, or method undisclosed

Full timeline

34 events from July 24, 2026 to October 7, 2026. Filter by type:

July 2026

  1. benilla, a World of Warcraft client rewritten in Rust

    A complete World of Warcraft 1.12.1 client, written from scratch in Rust on Bevy and loading data from your own install. It was an early sign that AI-assisted full-engine rewrites had become practical.

    samwhosung/benilla

  2. Nexus Mods expands its AI disclosure tags

    Two months before the wave, the largest mod host split its generative-AI tag into three (AI-Generated Content, AI Media and AI Assisted) and said undisclosed AI use could lead to moderation. Its guidance asks modders to avoid AI tools unless they have permission for every asset, which is one reason the mashups never appeared there.

    Sources: TheGamer, PC Gamer

September 2026

  1. skate-3-rust-engine is published

    A Rust/Bevy skating engine built from Skate 3 reverse-engineering research, with game assets loaded from your own copy. It became the most reused engine of the wave, behind the MW2 mashup and every GTA and Bully skate mod.

    SK8-ENGINE/skate-3-rust-engine

  2. IW4L, a Modern Warfare 2 runtime in Rust

    vladtrc publishes a standalone, experimental Call of Duty runtime in Rust on Bevy and wgpu. Because it and the Skate 3 engine were both Bevy codebases, they could be merged two weeks later.

    vladtrc/iw4L

  3. chasm: "I rewrote Skate 3 in Rust"

    The earliest known viral post of the trend. chasm (chasmlol on GitHub) shows Skate 3's skating running in a Rust rewrite, built with what they called a human-and-AI development loop. It passed 6,000 likes within a month.

    Sources: Know Your Meme

  4. Claude Opus 5.5 is released

    Anthropic's new flagship launches at about 40% lower cost than Opus 5 for typical workloads. Nearly every mashup of the next two weeks credits it. Cheaper long agent sessions made it affordable to point a model at a game's compiled code for hours.

    Sources: Unite.AI

  5. 2010 Rust Rewrite Mashup (MW2 × Skate 3 × Minecraft)

    Modern Warfare 2, Skate 3 and an endless Minecraft world in one Rust game, built from two AI-assisted engine rewrites.

    chasmlol/2010-rust-rewrite-mashup

  6. An AI-generated Banjo-Tooie PC port appears

    A native Windows recompilation of Banjo-Tooie whose README says AI tools generated substantial portions of the code. Within a week it was at the centre of the "slopcomp" fight (see 5 October).

    some-scurvy-dog/banjo-tooie-scurvy-dog-port

  7. Call of Duty × Minecraft hits YouTube

    A video of Call of Duty merged with Minecraft passes 619,000 views in its first week, the first mashup clip to break out on YouTube.

    Sources: Know Your Meme

  8. Minecraft in Elden Ring (viral clip)

    The most-viewed clip of the wave, reported at 22.5 million views, showing Minecraft gameplay in the Lands Between. No code has been released.

  9. World at War Zombies in the browser (P.E. Cooper)

    Call of Duty: World at War's first zombies map, ported to the web by Opus 5.5, then crossed with Wii Sports, Mario Kart, Portal, Fortnite, NHL and Halo.

  10. "Modding has Changed FOREVER…"

    chasm's YouTube round-up of the first mashups reaches 2.4 million views in a week. Compilation videos like it spread the clips far beyond X, often without crediting the original makers.

    Sources: Know Your Meme, VGTimes

  11. ER Mario (Mario in Elden Ring)

    Play Elden Ring as Mario with Super Mario 64's real movement: triple jumps, wall kicks, ground pounds and Bowser's tail swing on bosses.

    deltarooo/er-mario

  12. GTA Skate 3 Trilogy (Skate 3 in Vice City and GTA III)

    Skate 3 skating merged into the reVC and re3 source rewrites of Vice City and GTA III.

    irregularnetwork/GTA-Skate-3-Trilogy

  13. Halo: Combat Evolved runs in a browser

    Mitchell Hynes puts the original Xbox Halo in a browser tab, with the campaign, split-screen co-op and 128-player online rooms, built on a community decompilation. It's not a mashup, but it showed the same week how far AI-assisted ports had come, and that a browser could host them.

    OpenCommunityEdition/OpenCE · Sources: PC Gamer, Generation Amiga

  14. Minecraft in GTA V (universal-modder)

    Steve gliding an elytra over Los Santos and the Nether spreading through the city, built with an open toolkit for pointing AI coding agents at any game.

    rehan-remade/universal-modder

  15. SkyCraft (Minecraft in Skyrim)

    Play Skyrim as a Minecraft player: Minecraft's physics, inventory, blocks and combat in Skyrim's world. The passthrough mod that set the template.

    chasmlol/SkyCraft

  16. Tarkov in Skyrim (viral clip)

    Escape from Tarkov's guns, inventory and UI inside Skyrim. One of the first viral mashup clips; a follow-up added Spider-Man. No code released.

  17. The first explainers

    YouTuber LudocowTV's analysis of what the mashups mean for the industry passes 150,000 views in a week, as commentary channels start covering the trend.

    Sources: Know Your Meme

October 2026

  1. BullySkate (Skate 3 in Bully)

    Jimmy skating around Bullworth with the Skate 3 Rust rewrite, with controller support and rigging.

    Faiqie/BullySkate

  2. FalloutCraft (Minecraft in Fallout 4)

    A port of SkyCraft's passthrough design to Fallout 4: Minecraft movement, building and combat in the Commonwealth.

    zeyvu/FalloutCraft

  3. Tech press picks it up

    VideoCardz runs one of the first news write-ups, collecting the X clips from Minecraft in Elden Ring to Mario Kart in CoD Zombies. TweakTown and others follow within days.

    Sources: VideoCardz, TweakTown

  4. ArkWeb (Spider-Man web-swinging in Arkham Knight)

    Spider-Man Remastered's web-swinging inside Batman: Arkham Knight's Gotham, installed by Claude on your PC.

    luki-1/ArkWeb

  5. GTA San AnSkateas (Skate 3 in San Andreas)

    Skate 3's skating inside GTA: San Andreas through a C++ ASI plugin and the Skate 3 Rust rewrite.

    ryglizzy/GTA-San-AnSkateas

  6. Kotaku: "Modders, please stop"

    Amelia Zollner argues the mashups are made for social feeds, not for playing, and that none of the combined mechanics actually synergize. It was the first major outlet to push back.

    Sources: Kotaku

  7. OWCraft (Minecraft in Outer Wilds)

    Land on a planet, press F6 and you're playing real Minecraft on its surface. Built on SkyCraft.

    Yaekai/OWCraft

  8. The Mario in Elden Ring clip is taken down

    Deltaroo3D's clip of Super Mario 64's Mario in Elden Ring, at 2.9 million views and 60,000 likes, is removed after a copyright claim. The mod's code stays up on GitHub.

    Sources: Know Your Meme

  9. What's real and what you can download

    VGTimes goes through the viral clips one by one. Only a handful have code behind them (Mario in Elden Ring, SkyCraft, the MW2 skate mashup, the GTA and Bully skate mods). Most of the most-viewed clips have no release, and some no named creator.

    Sources: VGTimes, Everything Edinburgh

  10. Elden Ring as a shooter (Huberticus)

    Eight other games' mechanics and weapons inside Elden Ring, from DOOM and Halo to Titanfall 2 and Tony Hawk's Pro Skater 2. Clip only.

  11. Elden Ring combat in Skyrim (Rust controller rewrite)

    Elden Ring's player movement and combat rewritten in Rust from the game's own data, then dropped into Skyrim. The rewrite is public; the Skyrim mod isn't out yet.

    Funny-Bones/ELDEN-RING-Combat-Rewrite

  12. Melty, a launcher for mashups

    A free Windows launcher that installs mashups of games you own in one click, with multiplayer lobbies. New mashups are written by coding agents from instructions you paste into Claude Code or Codex. Melty is in Y Combinator's Fall 2026 batch, founded by David Miller. Some viewers questioned whether its demo clips came from other projects.

    melty.gg · Sources: Y Combinator, Developers Digest

  13. Modders push back

    VGC collects the reaction from established modders. A Kingdom Hearts modder says that if this becomes the permanent state of modding, their current project may be their last. Another calls the click-winning clips "jingling keys". The Banjo-Kazooie PC port lead says their project will never use AI.

    Sources: VGC, GIGAZINE

  14. The "slopcomp" fight

    The human teams behind Zelda and Banjo Recompiled disown the AI-generated Banjo-Tooie port, calling vibe-coded recompilations "slopcomps". They say it patches recompiled code from the wrong side, which makes it unmaintainable, and that building on their research by throwing AI at it is disrespectful.

    Sources: Kotaku, GamesRadar+

  15. Clean-room tributes you can play in a browser

    Five tributes to the best-known mashups (Blockrealm, Hollow Warden, Night Swing, Kickflip Ops and Block City) go live on this site. They rebuild the mechanics from observation with original code and CC0 assets, so they need no game files and run in a browser tab. Disclosure: this site made them.

    Play the tributes · andrewnakas/GameMash

Missing something, or got a date wrong? Add a mashup or edit the timeline on GitHub. See also all press coverage and the people behind the mashups.

FAQ

What is an AI game mashup?
A mod or program that combines the mechanics, and often the worlds, of two or more games, built largely by an AI coding agent. Examples are SkyCraft (Minecraft in Skyrim), the 2010 Rust Rewrite Mashup (Modern Warfare 2, Skate 3 and Minecraft) and ER Mario (Mario in Elden Ring).
When did AI game mashups start?
The wave started in late September 2026. The engine rewrites it grew from were published in July to mid-September, Claude Opus 5.5 launched on 22 September, the first mashup was released on 27 September, and the most-viewed clips appeared between 28 September and 5 October.
Who started the AI game mashup trend?
chasm (chasmlol on GitHub). Their 19 September clip of Skate 3 rewritten in Rust is the earliest known viral post, and they released both the 2010 Rust Rewrite Mashup (27 September) and SkyCraft (30 September), the template for most passthrough mods that followed.
Which AI model was used to make them?
Mostly Claude Opus 5.5, which launched on 22 September 2026 at a much lower price than Opus 5. Creators also credited Astra, DeepSeek V4 Pro and Codex.
Which AI game mashups can I actually download?
As of October 8, 2026, 8 of the 15 documented here have downloadable releases, including SkyCraft, the 2010 Rust Rewrite Mashup and ER Mario. All of them need your own copies of the original games. The most-viewed clips, like Minecraft in Elden Ring, were never released.
Are AI game mashups legal?
The released ones ship only code and load the games from copies you own, the way most mods do. Clips built from decompiled code or extracted assets are harder to share, which is one reason so few were released, why none appeared on Nexus Mods, and why the Mario in Elden Ring clip was taken down after a copyright claim. Clean-room mashups avoid the question by using no original code or assets.
Why was there a backlash?
Established modders and outlets including Kotaku and VGC argued that most viral clips were made for engagement rather than play, that the combined mechanics rarely interact, and that AI ports built on years of human reverse-engineering work were unmaintainable "slopcomps".

How this history is kept

Dates are first public appearance, in UTC. Dates of X posts are decoded from the post ID rather than taken from reposts. Repository facts (stars, downloads, licences, what a project credits) are read from GitHub and dated. View counts are attributed to the outlet that reported them, since they can't be checked independently. Clips without released code are marked video only and stay listed for the record.