What is a video game that you'd love to play, but no one has developed yet?

I played Stars! too! I simply adored that game. Who knows how many thousands of hours I spent as a kid on it. It somehow engaged whatever flavor of ADHD/Tism I have and I could get lost for days on it. It's funny, but even back then the graphics were absurdly simple, but we didn't care, the gameplay and complexity was so enthralling. Most of the game was just basic geometric shapes and numbers on a map, which seems hilarious now, but to me it proves that gameplay > graphics. Graphics can help, but the gameplay MUST be there first and foremost.