A good place to start with kids that age is Scratch: https://scratch.mit.edu/
The visual programming style may turn off experienced programmers, but it's a full game engine, there is a big community of other kids out there, and at this stage, programming is about basic concepts like variables, conditions, loops and functions, which are all represented here. And of course, game development is about more than code: Scratch also lets you add sound and graphics, and has an easy to use actor model.
There's also a neat voxel-based RPG engine called RPG in a Box (https://rpginabox.com/).
For Python, there's pygame, which requires a lot more code, but let's you make sprite-based games in a "real" programming language, if that's more your speed. Python also has classic turtle graphics, but that doesn't usually get you very far for making games.
Finally: I've used all of these (and other) tools with kids in that age group, as a mentor at events like Hack The Future (https://hackthefuture.org/) and Hour of Code (https://hourofcode.com/). Look for an event like this in your area, they are really fun to attend!
There's also a neat voxel-based RPG engine called RPG in a Box (https://rpginabox.com/).
For Python, there's pygame, which requires a lot more code, but let's you make sprite-based games in a "real" programming language, if that's more your speed. Python also has classic turtle graphics, but that doesn't usually get you very far for making games.
Finally: I've used all of these (and other) tools with kids in that age group, as a mentor at events like Hack The Future (https://hackthefuture.org/) and Hour of Code (https://hourofcode.com/). Look for an event like this in your area, they are really fun to attend!