Does the game in any way, shape, or form relate even remotely to Nintendo? Even a little bit? Even if it's just being made by some guy that at one point liked to play Nintendo games? Has its lead designer ever heard of Nintendo, in fact?
Then it's a casual game.
[And yes, I know the answers to all those questions, but I'm making a point that anything even minutely connected to Nintendo will automatically be labeled however naysayers want to help them maintain their worldview. Remember how many people saw the 3rd party sales during Christmas and were like, "Wait, I thought 3rd party games don't sell on the Wii?!" and were legitimately surprised?]