What’s the most fun program you’ve written on the HP-41C?

[helengrace]

Hi friends,
I’ve been playing around with the HP-41C and it got me thinking — what’s the most fun or unexpected program you’ve ever written on it? Maybe a small trick, a clever routine, or just something that made you smile.
I’d love to hear your stories and maybe learn a few new ideas along the way. Tunnel Rush Game