After completing stage 1, you may play the campaign levels in co-op as Lammy and Rammy. Players play simultaneously and are scored based on how well both players do. Completing the campaign unlocks a mode where you play as Parappa the Rapper, and completing his mode allows you to play a Lammy + Parappa co-op mode as well.
The game revolves around a shy lamb named Lammy, a left-handed guitarist of a rock band named MilkCan, alongside bassist and vocalist Katy Kat and drummer Ma-san. Although normally a nervous wreck, Lammy becomes much more confident once she has a guitar in hand.
This page contains co-op info for Um Jammer Lammy on the Classic. All information about Um Jammer Lammy was correct at the time of posting. Information is subject to change. If you see any errors please email us.