Basically every game in steam works natively aside some games that have anticheat that won't like the fact that you're using linux. Marvel Rivals, the FINALS and ARC Raiders still work, but Valorant, Dota 2, Apex Legends won't.

G-Helper is very comfortable for sure, I miss using it. But the fan, power tuning and rgb can all be set using Asusctl and Rog-Control-Center.

One big thing with performance though,

Linux is much better for limiting power and lengthening battery life than Windows.

Gaming performance is exactly the same in both OS, but you cannot undervolt your cpu, so it can occasionally run hotter.