She's obviously a Time Lord. That is the only plausible explanation. Nope. She totally didn't get a pre-released copy or anything.
....... Someone sees a bootleg game; automatic reaction is to freak out. I say ask her for the number of her Japanese re-seller.
She went to the future, got the game, and came back. And besides, she's Kitty. What law WOULDN'T she break for a video game?
It's obviously due to a Paradox in time. Nah, I know she has the game from the bundle with the Lightning PS3. So that could be it.
I know just the guy who can solve this question... Although, I think you freaked him out with the talk about paradox's. ...Oh dear.