What an amazing idea -- to create an actual G&W game! Congrats! Are you still planning to release some coding intro in the future? It's a pity that your website has changed and the old links no longer work... (though one can try to search in the Internet Archive)
And BTW, have you seen this Game & Watch "simulation" inspired by hit indie game Cuphead? -- https://dedjo0.itch.io/cuphead-game-and-watch-edition Also would've been nice in some "hardware" form...
Check out as well: KB1013VK1-2 Debugger for Soviet Nintendo Game & Watch clones (Электроника ИМ) -- http://www.ebastlirna.cz/modules.php?name=Forums&file=viewtopic&p=1130447#1130447