I'm somewhat surprised there's no demo/preview/marketing for any game yet. Seems like it would be hard to approach YC with "we want to make a game that makes tons of money", because there are a crazy amount of variables involved in that. Perhaps they applied with more info, but it's not public yet?
They don't have any games on their website currently but as far as I remember, they published their first game in January this year and generated a good amount of revenue
I'm guessing this is a pivot they've made recently- surprised they pitched it when so early: doesn't look like they are even at proof of concept yet with this new idea.
