For one of my upcoming projects using @tldraw.com, I needed a game engine like raycast, here's a couple solutions I came up with.
robertcorponoi.me/posts/raycas...

I wasn't happy with Doom running in a canvas in @tldraw.com so I made it run as shapes instead. Aside from the low resolution and the limited palette, it doesn't look too bad.
robertcorponoi.me/posts/tldoom...

Can @tldraw.com run Doom? Of course it can I don't even know why I wrote about this.

robertcorponoi.me/posts/tldoom/

Here's a demo with a cool flip that I got on the first take.