As a game, it lacked structure. It followed a fair amount of traditional "This is how it's done", but its story (and this is a big deal these days..) was not remarkably professional. It was cute, short, and more of a rush job the further you find yourself in the game. Honestly, once you run out of islands to explore, you're depending on habit and sheer will to beat the game. It could have been beautiful. It could have been what you caught just a glimpse of.. under the deep.
