AI-Decompiled Games Spread as Web Browser Ports

Hundreds of ports that decompile older games with AI and make them run in a web browser have appeared over the past few weeks. According to reports, hundreds of emulators and games decompiled with AI or built through vibe coding appeared out of thin air over roughly the past two weeks, and the reason cited was that Anthropic's latest model, Claude Opus 5.5, is extremely good at decompiling. The browser ports include Call of Duty: Black Ops, Halo: Combat Evolved, GTA: Vice City, Skate 3 and The Simpsons: Hit and Run. Some ports were taken down within hours of going up, but ports made the same way keep appearing.

Speed is the core of it. According to reports, reconstructing a game's source code, which used to take coders months, now finishes in record time. Native ports of Fallout and Call of Duty: Modern Warfare, along with mash-up mods that put Super Mario 64 inside Elden Ring, came out of the same trend. It is nothing new for a browser to handle these games. Most of the ported titles are from the PS2 and PS3 era; the PS3 had about 512 megabytes of RAM, while the reporter's web browser was using about 1,200 megabytes while writing the piece. What has changed, the report noted, is that you can leave Claude Opus 5.5 running overnight and have a game decompiled by morning.

The quality is high as well. According to reports, some of the ports the reporter played were borderline flawless. The port of The Simpsons: Hit and Run could target 240 frames per second, and one of the four Halo ports the reporter tried had working online servers, with low ping.

Among developers, attention turned to the web as a distribution channel. Jared Palmer, vice president of engineering at Cognition, wrote on X on the 6th that gaming decompilation, reverse engineering and web porting via WASM and WebGPU prove two things, saying that "despite all of its limitations, the web is still the best memetic distribution system ever created." He placed the URL alongside the wheel, written language, agriculture, the printing press, steam engines and the transistor, calling it "one of the greatest inventions of all time."

Pieter Levels, a solo founder who has ported classic games to the web himself, traced the trend's timing to accessibility. Instead of switching on a console or gaming PC, installing updates and waiting 30 minutes for a 50GB patch, you open a new tab, type the URL and the game starts. "I think game and console developers do not realize people don't have time to do all this," Levels argued. The post had passed 94,000 views at the time of collection.

Industry forecasts went further. X user Tenobrus, noting that one port was taken down within hours, predicted that within a few months, instead of sketchy torrent sites full of pop-up ads, there would be sites hosting fully playable free WASM versions of the latest AAA games. He wrote that because every input to AAA games that used to cost $100 million to $200 million is dropping by orders of magnitude in cost and time, the trend looks less like an existential threat to the gaming industry and more like a Cambrian explosion. The post passed 120,000 views.

Another case shows where the line of rights is drawn. On the 5th, mrdoob, the developer behind the 3D library Three.js, said he had ported Megacity, a demo Unity showed at GDC in 2019, to Three.js, running it at about 45 frames per second on a MacBook Air M1 and compressing the full demo down to 75 megabytes. Because of Unity's asset license, he did not publish a live link. Regardless of how fast code can be rewritten, the developer himself respected that the rights to assets such as graphics and models remain with their original owners. According to reports, lawyers for Take-Two and Microsoft can send cease-and-desist letters to get ports taken down, but ports that were quick and easy to make can simply be made again. The report described it as intellectual property whack-a-mole on a scale not seen since pirated DVDs.

METAL has reported that Anthropic unveiled Claude Opus 5.5 in September. In the original X posts that METAL reviewed, Palmer's post quoted Levels's, and Levels's quoted Tenobrus's, forming a chain; the three posts went up one after another within two and a half hours on the 6th (UTC). None of the collected sources contained an official statement from Anthropic or from game publishers.

From a rights holder's point of view, the issue lies less in the technique of making ports than in how they spread. The cost of making a single port has fallen to the price of running a model overnight, and the result spreads through a single URL. The report predicted that game publishers' legal teams will be working overtime for the foreseeable future. Whether taking posts down one by one can keep pace with how quickly they are rebuilt is now the question for the industry.