Yes, it’s a clone. Valve’s legendary first-person shooter (FPS) wasn’t exactly ported to Sony’s handheld, which was released more than 20 years ago.
Counter-Strike is one of the most popular first-person shooter games. On April 12, 2025, Counter-Strike 2 set the all-time record for concurrent players on Steam with 1,862,531. Despite being around for years with only minor updates, it remains one of the cornerstones of the FPS genre. That’s why the PocketJS modding group has been working to bring Counter-Strike to the PlayStation Portable (PSP), a handheld console that holds a special place in the gaming community. PocketJS released OpenStrike, an open-source FPS designed to run on original Sony PSP hardware. This Counter-Strike clone brings CS-style gameplay to the PSP with remarkable accuracy, a significant achievement for the modding community.
PocketJS posted a video showing the game being played and tested live on the PSP; it appears that DevTools was open. Clearly, the handheld runs the game smoothly, and the graphics closely match the original. OpenStrike appears to use the same classic levels, bots, trackers, recoil, and other game mechanics. The developers claim that the game runs at a steady 60 FPS on the PSP with a fully open JavaScript mod API. Most importantly, according to their estimates, running the game on the PSP requires only 12 MB of RAM. The PSP runs at 333 MHz with a native resolution of 480 x 272. OpenStrike is open source and reportedly runs on the original PSP-1000.
Behind the scenes, the engine uses the Rust programming language for bot logic, collision handling, movement, and rendering. The embedded QuickJS engine runs the entire heads-up display (HUD) and scoring system using TypeScript and JavaScript. The developers have implemented clever solutions to ensure that the game runs smoothly and without errors on the PSP. According to reports, lighting is compressed into peak colors, and the renderer skips processing invisible geometry. OpenStrike is not a port of Counter-Strike but rather an open-source alternative developed specifically for the PSP. While the game does not use Valve’s copyrighted maps or other materials, it still feels quite familiar. Currently, version 0.1 is more of a technical project than a complete multiplayer experience. It’s missing a few features, but it’s solid proof of concept nonetheless.
Players who want to try this open-source project can access the PSP EBOOT homebrew format on compatible systems. OpenStrike can also be run through the PPSSPP emulator. In any case, players must provide their own compatible BSP and WAD files.
Source: Tech4gamers
Yes, that’s Counter Strike on a PSP!
Yes, that’s DevTools inspecting game UI!
Yes, it’s PocketJS!Clean room implemented FPS engine, fully open JavaScript mod API, ~12MB RAM footprint, 60fps, fully open source. ⚡️ pic.twitter.com/OprLN3E71J
— PocketJS (@pocket_js) July 10, 2026
