I thought cookie clicker but with yubikey taps might be funny, and this is a proof of concept. Cloudflare did something similar in 2021, pitching yubikey-proven taps as a captcha replacement:

https://news.ycombinator.com/item?id=27141593

Cloudflare's idea of proving personhood with yubikey taps wasn't well received at the time. But here for a silly game, I think the idea holds up better. We can prove that you have a key, and serially tapped it a lot. If you automate activating the touch sensor on a physical key, you might be able to do a bit better. That's cool and you deserve to win.