Beta version of the Atari 7800 experiment can be played online or downloaded to play on an emulator from the links below:
Play online:
JS7800: Atari 7800 Emulator (raz0red.github.io)
Download ROM:
https://forums.atariage.com/applications/core/interface/file/attachment.php?id=1068178&key=14333a41e42244a3bf4f521ae984dff6

Watch video of gameplay: