Reply To: Enabling Atari 2600 emulation, is there a trick to it?

[SomeCoolName]

The likely issue is that your ROMs are in zip format. According to the github page, the accepted file extensions are .bin .a26 .rom.

https://github.com/retropie/retropie-setup/wiki/Atari-2600

If you want to use this system, you are going to drop in ROMs with a different file format.