The itch.io sandbox will try to prevent games you download from doing harmful things or stealing sensitive data. While it's not a complete safety guarantee, running games in the itch.io sandbox is much safer.
After clicking 'Proceed', a prompt will pop up, asking for your password. This is only needed when the sandbox is first used or updated, and your password is never remembered.
After clicking 'Proceed', a permission prompt may pop up, asking you for your approval. This will add an `itch-player` user account to shield your games from the rest of your system.