I don't think mobile games and Xbox games are the same market save for both competing for disposable income. Neither is a fit stand in for the other.

They also compete for a limited amount of time. There are very few console gamers who also don't have a smartphone or tablet with some games on it. They may not explicitly choose to game on their phone over Xbox, and they may acknowledge that they enjoy console games more. But on a given night, maybe they choose to watch tv, and second screen some games on their phone. And if that phone didn't exist, they would have chosen to play on their console. So they aren't equivalent, but they can still substitute for each other, and compete for time/money/attention.