While I had never personally been attached to the series, perhaps due to my later than target audience age, I found this game rather addictive and finished it over one weekend while travelling, playing simply in the mornings and at night. It does hold some replay value as it was considerably enjoyable to play, with well set out controls, missions ideal to the pick and put down nature of the PSP, but I had since forgotten about the game probably due to how short it was.
It's a recommended purchase if you see the platinum edition sitting around in a store at a low enough price. It's compelling enough to be worth the buy, but not worth paying a huge sum for due to the short story.