You assume the role of Lammy, the unconfident guitar player for Milkcan – one of the city’s greatest garage-rock bands. Like PaRappa, the more you play, the more the story begins to unfold. As time goes on, Lammy will slowly gain confidence and improve his skills in the genres of rock, punk, heavy metal, and pop-rock tracks.
The idea is to impress your teachers in each stage by keeping up with the rhythm. If you’re successful, Lammy is awarded Effecters — items that are used to provide a little extra oomph to your guitar licks. When you earn them, you’ll be able to break out with some wah-wah effects as well as distortion and pitch bends — using them correctly will help your overall ranking in each stage (based on PaRappa’s system of cool, good, bad, and awful).
Um Jammer Lammy allows you to challenge a friend in a head-to-head guitar-playing bonanza as well as save and watch your own games in the replay mode. PaRappa makes a guest appearance, but whether or not you’ll be able to find him depends on your skill.