Some updates for mobile visitors:
1. All of the games are flash based...and most mobile devices/mobile apps...don't support flash. But...there is a solution. To play the (flash-based) Arcade games on Mac-Forums...or to access any flash-based internet content...download & use the "Puffin" browser for mobile devices (it supports flash).
2. In my testing with the Puffin browser & the Mac-Forums Arcade...there's a full screen option that can be selected.
3. There's a "..." settings button in the lower right area of the window where you can select different input methods. I choose the "Gamepad" option.
4. Some games work better than others.
5. I couldn't figure out an input method to get Tetris to work (my testing wasn't extensive...so there may be a way)...but Space Invaders works great (I didn't test all the games).
6. More games will be added...hopefully they will work better via mobile.
This is primarily an update for mobile visitors...when visiting Mac-Forums via computer...everything works well for most users.
But more adding games in the near future applies to all visitors (computer & mobile based).
Thanks
p.s. The Puffin browser is available in the App Store for iPhone/iPad. There's a Puffin browser version for Android device users as well (Google Play Store).