Taken from the highly acclaimed Gainax anime series, you play a young inventor called Jean, who adventures with Nadia, a circus performer with a mysterious blue pendant. On the run from the evil Neo-Atlantians and their leader, Gargoyle, they find themselves making a strange discovery on a deserted island. The game also includes some quiz-based mini games.
*SERIES SPOILERS AHEAD*
The anime series is mostly excellent, but suffers a dip in quality when the studio decided to extend the run and add a set of what are essentially 'filler' epidodes. This happens right after the destruction of the Nautilus and one of the series' most dramatic and dark moments, and the shift in tone and character is highly noticeable for these episodes. They mostly consist of stories with Jean and Nadia stranded on a desert island and don't further the main plot in any way, while making you roll your eyes at the sudden stupidity of what is going on.
The game is set slap bang in the middle of these fillers, at a time when Jean and Nadia have met up again with Grandis' gang and Ayerton, giving the story writers plenty of characters to play with, and follows the exploits as they discover secret underground tunnels (similar to those in episodes 30 & 31), try to escape from Goblin (a Gargoyle lackey), meet a beautiful blonde who captures Jean's attention and face off with the threat of the Green Noah.
The game itself is a fairly typical digital comic format, with choices made from the menu, mostly consisting of look, speak, move etc, so it's easy for us non-Japanese speakers to progress without too much trouble. A couple of areas are a little labyrinthine, so you may find yourself wandering aeound longer than you wish, but aside from that the interaction is far more minimal. On the downside, the screen doesn;t have the usual ornate frame, instead a stark black background on which the pictures and test are displayed, however it does make up for this with some gorgeous artwork and that fact that it's fully voiced.
Digital comics are a hard one to rate as it just depends on what you like. I really enjoyed The Secret of Blue Water both before and after watching the anime - the story is easy enough to follow, there's plenty to look at and it rarely slows the pace down. The plot is in keeping with the bulk of the series and would have been a far better choice that the block of fillers that ended up in the actual show. It's certainly one of the better sigital comics I have played, perhaps not as good as Ranma, but almost.