This is a pre-order, released on 21 November 2008.
RRP £19.99 (I believe).
If you go via Quidco, effective price is £12.99.
Second lowest price I could find was £16.39 (WH Smith), Play & HMV have it for £17.99 before any discounts.
EDIT: Sorry, I have noticed that this has been posted before (quite a while back with an earlier release date). At least this might draw other people's attention to it? Maybe it will finally be released!
"LocoRoco is back with a bounce, a roll and a splash in another joyous adventure on PSP.
The LocoRoco are in danger again, the evil Moja have returned and this time they`ve brought with them a terrible song that sucks the life out of living things! The LocoRoco must once again save their planet - this time by making lots of sweet music.
LocoRoco 2 is easy to play, instantly addictive and guaranteed to make you feel all warm and fuzzy while you hum along to the soundtrack!
Explore 25 new stages, including hidden challenges, and meet a colourful cast of new characters.
Enhance your LocoRoco through music and song, learning new actions to overcome the Moja.
Perform new actions such as climbing inside shells to destroy thorns, jumping from grass blade to grass blade and swimming underwater.
Expand your fun with six new mini games, including an Ad-hoc four player game."