While the macOS Finder icons changed quite a bit over the years – my custom made icon for a “Games” folder did not keep up.
Until now…
Download the Games folder icon for macOS
Update June 19, 2021: with more UI changes in recent macOS a new version of the icon is available here.
The style and design is optimized for macOS 10.15 Catalina, but should work with prior versions down to 10.10 Yosemite:
Simplified version 
Detailed version
Like I stated back in 2008, the new version is still not a 100% perfect macOS styled icon. But it gets it’s job done IMHO. But what do you think?
Doesn’t show well in the icon bar, has white around it. You need a transparent version