Unsoldered Gamer Kit
This is a solder kit to make a Gameboy-like handheld with an Arduino Uno and then design simple games that you code in C++ yourself. It also includes some familiar games to show off the concept such as snake and breakout. The instructions on the site below for both the soldering and programming elements are fantastic and I fully recommend the kit for children and adults alike. Adult supervision and some prior programming experience would be useful.
https://make.techwillsaveus.com/gamer-kit-unsoldered
There is even a git repository for the included libraries; https://github.com/techwillsaveus/Gamer
Here is the first game that I wrote after soldering it all together, it's called Dot Collector...
Simon says
My next game to recreate, should I ever have time, would be to recreate the game Simon says
Pathfinder
Similar to Dot Collector but the path to the dot to collect needs to be swiftly memorised as you will need to navigate to the dot whilst the screen is blank!