I found this uploaded at another site, it works on 2.71 SE-B'B (probably works on all 2.71 SE, but you should update to the latest one)
It was uploaded at rapidshare, so I rehosted it at sendspace.
Copy it to \psp\game\game271\LRHD\eb oot.pbp
So yea, enjoy!
(BTW, the folder the eboot goes into, it doesnt have to be named LRHD, you can name it anything, I named it that for "LocoRoco Halloween Demo" and also, I didnt mod it for 2.71, someone else did.)