The GameTank is an incredibly cool project. I first saw an ultra early model with only sound capabilities before the covid pandemic, so seeing it finally live on CrowdSupply is a testament to the hard work and dedication of its creator, Agumander.
I won't go into technical details of the console here. You can find more information about it on it's website [0] or it's github repo[1]. You can check the console out with its emulator[2], which can run in your browser with the game listed here[3]. I also wrote a post about developing a game for the GameTank[4], which might give an idea of what it's like to make a game for the system.
[0] https://gametank.zone/
[1] https://github.com/clydeshaffer/gametank
[2] https://github.com/clydeshaffer/GameTankEmulator/
[3] https://gametank.zone/games
[4] https://nickgirardo.com/posts/avhg-thoughts.html
