For younger kids I've modified Overcooked 2, a traditionally co-op game. I've replaced the second player with a visual scripting platform that allows kids to code their way through levels — worth noting I haven't removed co-op, there's still room for 2 other players:
https://www.youtube.com/watch?v=ackD3G_D2Hc
For older kids I've been making contributions to GodotJS, which allows you to build games in Godot using TypeScript rather than GDScript. GDScript is pretty nice, but I want to be able to teach kids skills that are more directly transferable to different domains e.g. web development:
https://github.com/godotjs/GodotJS/pull/65
I used to be Head of Engineering at Ender, where we ran custom Minecraft servers for kids: https://joinender.com/ and prior to that I was Head of Engineering at Prequel / Beta Camp, where we ran courses that helped teenagers learn about entrepreneurship: https://www.beta.camp/. During peak COVID I also ran a social emotion development book subscription service with my wife, a primary school teacher.