It reminds me: a decade ago, I had the idea of porting Baldur's Gate 2 to the web: http://lumakey.net/labs/battleground/demo1/ I initially played with EMSCRIPTEN as well, starting from GemRB, an open-source reimplementation of the engine. But that was boring, as I wasn't really getting any sense of how things were working under the hood. So I started reverse-engineering the various file formats (a website called IESD…
I got pretty far but there would have been years and years of tweaks to get it just right, so I gave up.