Unreal previously had built in support for asm.js + WebGL, so it's pretty reasonable to expect that you can compile UE5 games to WASM. The question is whether they will run, and it looks like the people responsible for this demo have ported the renderer, which is a big part of the equation. You would also need to port things like input, sound, filesystem and networking, but since they're loading textures and models, filesystem is probably ported too.
The browser is still pretty bad for deploying large applications like a UE5 game, so your guess is as good as mine when it comes to 'will people be able to actually ship this way'.
I remember their 'citadel' demo. I recall it disappeared rather quickly. All that seems to have survived is a youtube video of it. https://www.youtube.com/watch?v=c2uNDlP4RiE
> The browser is still pretty bad for deploying large applications like a UE5 game
Please wait, downloading 80gb of content....don't refresh page or clear browser cache...ever
I do appreciate the achievement here, but it's not something I personally would want.
Most of the code isn't source code but assets and those can be streamed.
Realistically even the toughest AAA games can be tuned to few GBs of code and the assets required for the initial area. I remember on UE4 you could compile the entire executable with some small game in waaaay less than a GB without particular difficulty. You can use this approach and stream the rest later.
This is especially doable if you keep the game state and menus/UI in the html + JS and avoid that part of UE entirely, so you just launch whatever is your map and game and those states.
Streaming is much better option, latest hardware instead of 2011 WebGL and 2015 WebGPU, and guarantee it works on the client without having to worry about black listed GPUs and drivers, leaving a empty black box for the user to see.
The browser is still pretty bad for deploying large applications like a UE5 game, so your guess is as good as mine when it comes to 'will people be able to actually ship this way'.