Is your conclusion based on the fact that you do not consider a computer a musical instrument?
And I would argue that your comparison with the game is a little off base. When you ask, "...does it make me an athlete...???" I don't think there's enough evidence in the scenario to make that conclusion.
If you asked, "...does it make you a football player...???" then the answer is clearly, "No".
But one could argue that the instincts and ability to physically execute the moves needed to be proficient at that particular game do make you an athlete.
In other words, a novice to the game could try to play, but not be physically or mentally able to be competitive. Because you, the Madden Football expert, developed your hands and mind to a certain level of expertise, one could make a case that you did what other athletes do - trained, practiced, built up your muscles and mind toward to goal of being competitive at a game.