A relatively uncompromised portable version of Pop'n Music. The song list of heavily truncated from arcade versions, but there's still 80~ songs to pick from, ranging from PM3 songs to anime OPs. A good amount of the cast is selectable too!

The major issue is that Popn music on intended controllers is fucking hard. Playing this on a PSP is a major learning curve, and if you're willing to grind that out, you're probably better off just building a con with 9 buttons and grabbing a proper arcade rip.