What Mobile Game?

[Kokoro]

So, long story short.  I'm looking to leave my 9 to 5.  (My feet are killing me.)  I do have some experience with Unreal Engine, and I want to create an anime mobile game, but I honestly 1) don't know what I want to build, and 2) I don't really know what people crave.  Help a girl out?  If there you could play any game that's not currently on the market, what would it be?  What would you do (the goal, or point of the game?)