How do I play these games?

Unless you own original hardware (chances are you don't), your best bet is using an emulator. Since the 3DO was never a particularly popular gaming system, not many emulators exist. Recommendations: 4DO (Microsoft Windows) or RetroArch (all other systems).

As you can see, we don't have decent instructions here yet. If you have questions or if you want to help fill this gap, head over to the forum.