I almost said something naughty. Instead, I am just implying it with this comment. Anyway, it can be single-player and multi-player, depending on what you want—even a group effort.
Ok, my idea is kind of out of the box. here goes: What if its a game that can be played with multiple people across the globe, in real time, but not while in contact through social media or the internet because this would imply the use of electricity. Can anybody imagination create such a game?