It is a WebAssembly-compiled version of the emulator via Emscripten.
Key bindings
Enter - start/pause the game
Space - jump
F - fire
Arrows - move
Try it now
Source code
You can find the original source code here.
It is a WebAssembly-compiled version of the emulator via Emscripten.
Enter - start/pause the game
Space - jump
F - fire
Arrows - move
You can find the original source code here.