We created this css-only memory game as an experiment at one of our company days' hackathons. You can try it out here: https://edmdesigner.github.io/memory-game-in-email-poc/
Video: https://twitter.com/chamaileon_io/status/1356239378733916161
Supported email clients: https://www.caniemail.com/search/?s=checked
You can achieve support for Gmail if you send it as an AMP email. (You will have to make some changes, for example replace the img tags with amp-img.)
We are planning to introduce similar interactive functionalities in our APP and SDK.