There are a few versions of the game (same name but different levels and gameplay) which is a weird choice, but one was for the current gen (Xbox 360 etc) and the other was for previous gen (Xbox), ...

The best-selling Tom Clancy's Splinter Cell® saga takes on an entirely new direction. Play as a double agent spy for the first time ever in Tom Clancy’s Splinter Cell Double Agent™. Take on dual roles ...