I just finished this game, and I think it is one of the games I had the most fun with this year. It's much longer than the first one, as Fien said, and allmost all the puzzles are logical and can be done in more than one way. I like that a lot.
Spoiler:The endings were sad, however. Mina has a bad fate, the poor girl. She tries so hard to get off the island, and in the end it is all in vain. It almost brought tears to my eyes.
I didn't really get the resemblance Nemo talked about in the game. Is Mina a descendant of him?