If you know something about wiring you can get photocells and wire them to the paddle ports (pin 9 and 5) then move by how much light gets to the photocell. I put two in a piece of wood so I could use my hand to allow or restrict light reaching the photocell. Also fun to write a basic program to take the value and use it for the sound command. Makes some weird noise.

That seems fun. I have a kid who might love to play with one or two hooked up to the sound registers.

Edit: I know what I am going to do. My granddaughter is 5.

I am going to write a little basic program that reads these cells wired to a couple paddle ports. I have one set I can take apart for this bit of fun. We have two hands, which makes for a perfect pairing.

https://www.atariarchives.org/ecp/chapter_5.php

Press a key, and something happens on screen. Maybe the color changes with the sound, or it says, "Hello Kiddo", whatever.

And the registers, math, change.

A couple hours on this should lead to interesting time watching her interact with it all.

Thanks for the inspiration. Should be fun. Now all I have to do is get a program into that Atari. Might finally be time to get one of those SD card devices for my Atari, or a FujiNet. Something.

Young kids love that game. I have a good version for the VCS. Medieval Mayhem.

It never fails. Mine and friends will play that one for some time. It is simple, immediate on a low latency display and all interactive.

Total classic!