but I do wonder if BEAM is a bit of an overkill, even fly.io (known among developer threads to be very unreliable uptime) wouldn't be my first pick.
Cloudflare Durable Objects really is generous, not often can you get replicated database and realtime sync for such low barrier in cost and implementation.
I do wonder tho what Cloudflare's ultimate game is, as I'd imagine once they corner the market and practically everything is running off it, wouldn't be hard to say raise the $5/month to something higher.
Aside: The links to the web game in the post don't lead to being able to play.
It's a very productive and readable programming language with excellent documentation and conventions, and the most ergonomic way of handling concurrent operations (thanks BEAM) I've encountered.
The VM it runs on was originally designed for telephone switches, which, it turns out, cleanly translates to the internet/http era.
It makes it trivial to do soft-realtime because it's just actors (GenServers) passing messages.
I invite you (and others) to try it out and do a small weekend project. It'll make you reconsider reaching for TS on the backend :)