Relaxing, good puzzle game. Make sure you play when you're chilled out else you'll just get annoyed quickly.
First got to play this game on Christmas day as that was when I got a PSP, nice relaxing game - music goes well with the game and I like the sounds of the objects and the mercury.
I think they could have turned the music up a bit more, I did turn the effects down in the options but the music is still a bit too low, it's best to play it with the headphones that come in the PSP value pack, you can then hear all the music and the sounds perfectly. But that's alright, you just might want to turn the effects down a little to hear the music better...
Anyway, the graphics are better than what I have seen in images and on videos, the mercury is very well done (my Mum noticed straight away it was mercury - she didn't know that it was meant to be or anything (she used to play with it in school :O) so it's not just any old blob of in-game metally stuff.)
The game can get quite hard in places but I have put the difficulty as 'Just Right' as all puzzles get hard in places. They're meant to.
If you like a relaxing, original puzzle game then get this :-)