If you miss the games from the arcades of the 80s, or the classic Mac, Apple II or other systems, you can still play a lot of them on your Mac today. They are free and you don't even need to install anything.
Check out Playing Classic Games On Your Mac at YouTube for closed captioning and more options.
Some links directly to sections of the Internet Archive:
The Internet Archive was a fun reference. A very nice internet secret (at least to me). Thanks.
Gary, have you used OpenEmu? It has been around for some time and I've read positive reviews but not downloaded their emulator. Just wondering if you would have any cautions about using it.
Steven: No cautions, it is just that for most people it isn't a good option. You need to creator (or find) the game ROMs on your own and add them in separately. If you feel that is something you can handle, then that's good. But otherwise it is much easier to do it the way I show.