God Of War On PSP, Recompiled To WebAssembly And Running In The Browser

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A GitHub project translates PSP game code into C++, compiles it to WebAssembly and runs it in a browser with a custom PSP software layer and WebGL2 graphics. Its author reports playable demonstrations of God of War: Chains of Olympus and Ghost of Sparta, but users must supply their own game data and performance varies by browser and device.

A GitHub project has demonstrated God of War: Chains of Olympus and God of War: Ghost of Sparta running in a web browser after their PSP code was recompiled to WebAssembly. Rather than including game files or relying on a conventional emulator, the project translates a game’s machine code ahead of time and supplies a browser-based reimplementation of selected PSP hardware and system functions.

The repository author says Chains of Olympus runs from startup through menus, cutscenes and combat, with music, dialogue and sound effects working. In scenes measured so far, the game reached 60 frames per second in Chrome and Firefox on a laptop, at resolutions up to four times the PSP’s native 480-by-272 pixels. The author also reports support for phones using on-screen touch controls. Movies are currently skipped.

Ghost of Sparta was brought up using the same scripts and recompiler, according to the project report. It required additional handling for a small DRM-protected file, several system calls and a lighting correction. The author reports performance of 55 to 60 frames per second at three times native resolution, without separate performance tuning for that game.

The build process analyzes a decrypted PSP executable and emits C++ code, which is compiled to WebAssembly. The generated game code runs against a model of PSP registers and memory, while a compact software layer handles operating-system services such as files, controller input, audio and save data. Graphics commands are decoded and sent to WebGL2; audio uses browser audio facilities. Disc data is read as needed through HTTP Range requests, rather than downloading all of it at startup, the repository says.

A Different Route to Browser Play

The project is a demonstration of a different way to run older console software on the web. Instead of interpreting each PSP instruction as the game runs, its recompiler translates the executable ahead of time into C++, then relies on WebAssembly and browser graphics APIs. That approach could reduce some of the work performed at runtime, while still requiring software that reproduces the PSP services and graphics behavior the game expects.

Its practical reach is more limited than a hosted game service: the repository does not include game data. Users must provide a disc image they own and run the conversion scripts locally. The demonstration also does not establish compatibility with PSP games generally; the reported results cover two titles and depend on game-specific fixes. For preservation and accessibility, however, it offers a technically notable example of PSP software running through ordinary browser technologies on computers and phones.

How the PSP Build Works

The project’s graphics layer handles PSP display lists, including vertex processing, lighting, textures, clipping and framebuffer effects, before passing batched work to WebGL2. A separate worker thread runs the graphics engine using an OffscreenCanvas, allowing the game code to prepare another frame while graphics work continues. The author says this arrangement matters because PSP games commonly overlap CPU and graphics tasks.

The repository describes performance work as a substantial part of development. An early playable version ran at 6 frames per second, according to the author. One reported bottleneck was the game’s framebuffer-swapping behavior, which caused it to draw multiple frames for each one shown. Changes to synchronization reduced that unnecessary work. The report also describes browser-specific issues with WebGL buffer handling and profiling timers, as well as a reduction in extra pixel processing for effects that use the PSP framebuffer’s alpha channel as stencil data.

Getting Ghost of Sparta to start exposed another compatibility requirement: the game checks a small file protected using the PSP’s PGD format. The project added code to handle that file and its decryption. These examples show that translating executable code alone is not enough; a browser port also has to answer system calls and reproduce behaviors expected from the original console.

“The first playable build ran at 6 frames per second.”

— Project author, in the GitHub repository

Compatibility and Performance Limits

The reported frame rates are the project author’s measurements, not results from an independent test. The repository describes performance in scenes measured so far and identifies Chrome and Firefox on a laptop, but does not give a full device list, benchmark method or results across a broad range of hardware. Its mobile claim does not specify which phones or the frame rates achieved on them.

It is also unclear how reliably the scripts work with different disc images, browser versions or operating systems, and the report does not establish compatibility beyond the two named games. Cutscene movies are skipped, and other titles may require further system-call, graphics or copy-protection work. The project says users must supply game data, but the report does not provide a general compatibility list or independent verification of ownership checks.

Further Games and Browser Testing

The project is available on GitHub, where its scripts and implementation can be reviewed. The next useful milestones would be broader testing across browsers and devices, clearer compatibility guidance, and further game ports that show how much title-specific work is needed. The existing report says Ghost of Sparta ran through the same scripts without changes to the recompiler, but it does not announce a release schedule or name another game in development.

For now, readers can treat the work as a technical demonstration rather than a ready-made way to play a library of PSP titles online. Any wider assessment will depend on reproducible performance results, documentation for preparing game data and evidence that additional games can run with the same approach.

Key Questions

Are the games running in a PSP emulator?

The repository describes a different method: it translates decrypted PSP executable code ahead of time into C++, compiles that code to WebAssembly and connects it to a browser-based implementation of PSP system and graphics functions. The project characterizes this as running without an emulator, though it still reproduces parts of the PSP environment in software.

Which God of War games are demonstrated?

The project report names God of War: Chains of Olympus and God of War: Ghost of Sparta, both originally released for PSP.

Does the repository include the games?

No. The author says game data is not included. Users provide their own disc image and run the repository’s scripts on their machine.

How fast do the games run?

The author reports 60 frames per second in measured Chains of Olympus scenes in Chrome and Firefox on a laptop, at up to four times native resolution. Ghost of Sparta is reported at 55 to 60 frames per second at three times native resolution. Those figures are project-reported results, not independent benchmarks, and the report does not give comparable mobile performance figures.

Are all game features working?

The author reports working gameplay, menus, cutscenes, music, speech and sound effects for Chains of Olympus, but says movies are skipped. The project report does not claim complete compatibility across all PSP games or every feature of the two titles.

Source: hn