Depends on the title and the nature of the anti-cheat code. If it basically acts as a system-level rootkit, then you may be out of luck.

I’d check the big community-driven games database that keeps track of compatible games here: https://www.protondb.com/

In some cases, minor tweaks and settings changes will make games work fine, even if they’re not officially supported.

As for GoG games, there’s Lutris and Heroic Games Launcher, both of which can use Steam’s compatibility layer for running Windows-only GoG games. Again, there may be tweaks involved and your mileage may vary, but the communities for both are extremely helpful.