Stage 1 of Um Jammer Lammy was incomplete in the original PlayStation version, not being accessible in either multiplayer or PaRappa's story. With a GameShark code, a US player can access an unfinished version of PaRappa's stage 1, which has no animations and only uses triangle buttons. Stage 1 would eventually be finished for Um Jammer Lammy NOW!, released 9 months after the PlayStation version, with Rammy and PaRappa support.

Stage 1 is the only PaRappa stage to use the instrumental of the Lammy version.