I just finished the game about an hour ago. It was just as excellent as the first one for the first 3/4 of gameplay. Then unfortunately it seemed that they ran out of things to do or got tired of programming things to do and just threw in a whole lot of cutscenes. I don't mind the occasional cutscene that lasts a minute or two but man these ones just seemed to go on and on with the diving down, coming up, diving down, coming up...AARGH.
But I will be in line when the next one comes out!