Yeah, it won't wreck your game. You can turn it off between matches as soon as you feel yourself going braindead (as long as one character is a human). I actually did both of these requirements-- played 20 hours and 700 matches-- just so I could say I did and get the food trophy. I was about to smash the game to pieces when I was done with all that.
On November 21st, Nintendo will unleash the greatest handheld system on America that this world has ever seen. Two screens, two extra buttons, one touch-sensitive screen, wireless multiplayer, voice recognition, a rechargeable battery, and more. Prepare to severely wet yourself.