I originally made this experience about 2-3 years ago in Unreal Engine. The resulting build was huge: over 6 GB to download in order to play for max 10 minutes. Needless to say there weren't that many people that ended up playing the game.
Seeing the quality that's possible to achieve nowadays in the browser using gaussian splats, I recently got the idea to port it to a web-based experience. The result is that the whole game is a bit over 100 MB, and that's including about 20 MB of music and VO. Thanks to Spark's streamed LOD system, you don't even have to have everything downloaded by the time you start playing.
I've learned quite a bit about gaussian splats along the way, the main takeaway being that using splats for VFX inside a splat scene is still a bit of an unsolved problem (there's no way to decouple the VFX splats from the rest of the scene while keeping occlusion, and mixing static LOD'd splats with animated VFX splats leads to lag when LOD changes).
Let me know if you have any feedback or questions, and I'll do my best to answer them later tonight or tomorrow. Cheers!