Also what is the difference between MathAcademy and Brilliant? I have read many skeptical opinions on Brilliant, so it would be interesting to have a comparison.
My first game (not available anymore, but it was this: https://www.youtube.com/watch?v=cQfMHzbFL-w) sold maybe a few thousand copies, but it briefly hit the front page of reddit, indirectly led to some other fun opportunities, and got the chance to get a feature on the App Store (...though I didn't see the email until way too late), which was probably some of the most fulfilling stuff that has happened to me online, as someone that keeps a minimal online presence otherwise. But commercially? It would be considered an abject failure by any studio that had to keep the lights on. As far as hobbies you don't have to leave your desk for, game development carries with it so much possibility. Which is also what makes it so dangerous and alluring for so many, I think.