Even at only v1, along with the "don't break the web" mentality, Web Components are an extremely important stepping stone. We should cheer the implementers of these proposal on and help!
We can now render whatever content we want confidently, inside of other apps. Less than an iframe, but enough isolation (or not if you want) with all of the important benefits of being baked into the current document.
I've tested https://kherrick.github.io/sprite-garden/ by pressing, "W", "↑", or "space bar" to get started moving in the game. Afterwards the other functionality seems to work as expected in Firefox on Linux with the following versions:
- 140.3.1esr (64-bit)
- 143.0.4 (64-bit)
- 145.0a1 (2025-10-02) (64-bit)
Are you able to describe what issue you are seeing in particular?
Its sort of a "P2P mesh" :-) Watch four instances of the harness running together and collaborating on checking the weather: https://www.youtube.com/watch?v=h1les1A3gcg