Andrew is correct in stating that LocoRoco is hard not to love, but it's a love that's difficult to maintain.
My fellow Critic is entirely on the mark when he describes the game's sharp visuals and catchy melodies. I'd be very hard-pressed to pick another game on the PSP which is as memorable in terms of audio and visuals as this one is. It stands out, has its own style, and is impossible to mistake for anything else. LocoRoco has personality in spades. What it does not have is gameplay.
Don't get me wrong-rolling happy blobs through cheery landscapes is both pleasantly simple and warmly engaging, but only in very small doses. Within the span of a few brief levels, the initial attraction wears thin while the expected introduction of new elements needed to keep the experience fresh never occurs.
On one hand, I think that more games should take the LocoRoco approach by being easy to grasp and very welcoming to a wide spectrum of players. Far too many games require previous experience speaking the abstract, idiosyncratic language that lifelong gamers learn over the course of years. On the other hand, LocoRoco never goes anywhere after introducing itself and fails to capitalize on its significant potential by remaining as basic and effortless at the end of the game as it is in the beginning.
It's not that I necessarily want a higher degree of difficulty, but the formula of rolling here, jumping there and collecting LocoRoco bits along the way is not enough to sustain an entire adventure. Even a brief game completed in a matter of hours starts to feel overlong and tired when the developers don't ask me to do much more than avoid spikes and keep moving.
I give the game all due respect for its visual and auditory creativity, and it also gets high marks for being so approachable, but its goal for the gameplay was set too low. I fully believe that even the greenest newcomers will be able to grasp LocoRoco's core mechanics by the end of the first set of levels, and it's a shame that the developers felt simple repetition of the beginning segments would be sufficient for the entire length of a project that's attracting as much attention as it has.
I sincerely wanted my LocoRoco love affair to last longer and to burn brighter than it did, but it wasn't meant to be. It's fine for a brief fling, but personality and charm can only get a game so far...without anything under the surface, LocoRoco is an experience that's as shallow as it is charming.