I think it has more than 64 tbh. Well in regards to games that hold up to today's standards. But tbh if its mostly limited to first party releases, it's not gonna be massive.

Yeah, my hope for GC on NSO would them adding some more obscure third party stuff from developers like Capcom since they've supported the service for the other consoles on NSO. Imagine if Gotcha Force got added, would definitely be interesting to see.