"I’ve been using Zorin OS for 159 days, and I’m facing a frustrating issue with games on the itch.io app. When I launch a game, the screen freezes—it becomes completely unresponsive. The game runs terribly, and even simple actions like adjusting the volume or brightness cause problems. I desperately need a solution to fix this."
Are you downloading the game or running an itch application? Or running games from the web browser?
From what I can tell, many of the games on Itch are built using Unity. Unity is finicky with libraries, especially when used with a compatibility layer like proton.
I use itch, I downloaded it from flathud, I play horror games but the screen is black or moving slowly even though my device is powerful
It surprises me that it is offered as a Flatpak, given that running it in a sandbox is a known issue.
I looked at the itch supplied app - it comes as a Self Installer. It gives no indication on the surface what format it installs in, where it downloads it from or what it downloads.
I prefer to not install this mystery application just to learn that information... But given that it just runs, without checking any system configuration, I would think it must be a flatpak installer.
But the itch app was sandboxed already... As a non-flatpak.
You might try using portals to give that application graphics or system permissions using the Flatseal application, which gives a user access to providing any Flatpak broader permissions and access.
Welcome to the Forum!
That you use it as Flatpak could be a Point. Because Flatpaks run containerized, there have only limited Permissions.
Another Thing: How are Your Hardware Specs? And does Your System run in Wayland or X11? You can check that in Settings>About.