Could it be your hardware being on the low-end side? I’ve played a variety of Itch.io games before, including web games and installable games from the Itch app, and never had a similar issue. 30 minutes sounds like a crazy long time.
I don't thinks it's a hardware problem, I have tested in different machines with different internet connections, it's like a problems that appear and dissapear in a random way. sometimes it works good, sometimes it doesn't
