The return of the first PaRappa's beloved Chop Chop Master Onion (''Punch! Kick! It's all in the mind!'') will make you cry. But not tears of joy. Instead, you'll mourn the total lack of innovation in this sorry sequel. Maybe PaRappa 2 just has too much to live up to: The original, released in 1997, was a refreshing change from the countless shooting, racing, and adventure titles that flooded the market. For those unfamiliar, PaRappa is a lovesick canine who must learn how to rap. Players hear a track, which they must tap out on a controller to advance to each new and more rhythmically complicated level. The songs are maddeningly catchy and as integral to the gameplay as animator Rodney Greenblat's lovable, low-tech 2-D characters. P2 reprises these pleasures and has more varied tunes -- but sadly, the old dog hasn't learned any new tricks. THE ASSIST Complete all eight stages with a ''Cool'' rating to unlock a jukebox featuring the game's soundtrack. THE LAST SHOT If you've never rocked out with Um Jammer Lammy before, get ready to boogie down. Otherwise, it's more, more, more of the same.