Thanks a lot for the feedbacks! I spent quite a lot of time on this yes, though I was already quite familiar with 3d rendering and astronomical computation so it wasn't that hard. In fact the most difficult part was probably to learn WebGPU that I never used before.

For the issues:

1. Yes there are some bugs currently with the temporal anti aliasing. I was a bit aggressive on the effect because without it the Milky Way doesn't look good. I'll try to fix that (ideally it should adjust to the the velocity field).

2. All the time controls is still pretty much untested, I'll see if I can fix that.

3. I'd like to add more scale hints, but it's hard without cluttering the view. I'll see what I can do.

4. Yes at the moment there is only one black hole (sgr A*), I'll add more as soon as I can.

As for how this will evolve, I am not sure yet. I have a basic mobile version prototype working on iOS, so I thought this could turn into a mobile app at some point. No plan for an actual heavy PC app at the moment.