Massive improvement on the Parappa formula.
It's very similar to Parappa, right down to the paper thin graphics, but there are many things added that make it more than just a simple rehash. The first thing you notice about Um Jammer Lammy is the fact that (until later) in the game you don't play as Parappa, instead you control series newcomer Lammy and instead of rapping to music, you play your guitar. This works in essentially the same way as rapping, you press buttons on the controller when they appear on the screen to get a rating of Cool, Good, Bad or Awful. Like in the first game, in order to get a Cool rating you have to do a bit of improvisation with your guitar, which allows you to rock out with your own guitar solo. This time around there are a few added features, though. You can hold down L2 and R2 to change the pitch of your guitar and throughout the game you can unlock tools to alter your sound, e.g. distortion, wah wah. The story revolves around Lammy sleeping in and racing against the clock to get to her concert on time. In a dream she meets up with Chop Chop Master Onion (returning from the first game along with several other characters) who teaches her that "her guitar is in her mind." She somehow uses this advice to overcome various obstacles in her way by playing objects (including a hose, chainsaw and even a baby) like a guitar. While Parappa used hip hop style music in levels, Lammy uses rock music. The new songs are just as catchy, if not more than Parappa's and allow for a greater range of styles between levels, anything from Rockabilly to Metal. Like Parappa, the single player mode is short lived, but after the game is beaten, a heap of extras are unlocked. These include the ability to go either head to head or co-operative against a CPU or a second player. Even better is the fact that it allows you to play as Parappa, featuring a completely new (but slightly worse) soundtrack. These extras are what makes the game solid and adds much more time to the life of it.
Um Jammer Lammy is a very good Rhythm game. Anybody who enjoyed Parappa the Rapper should pick it up.