Visually, Nemo stays very true to its source material. Underwater environments are beautifully rendered and carry with them a sense that you're really underwater. Plant life sways along with the current and schools of fish swim around you. This gives the game's worlds a real sense of life. More watchful eyes will even catch smaller details such as water giving your character a slight pull or push depending on the current. Characters are rendered very cleanly and accurately. The in-game renders may pale a little after watching some of the CGI scenes from the movie (which are dispersed throughout the game), but they're pretty close.
A subtle soundtrack and effects compliment the game's atmosphere. Unfortunately, there are times when things get a little too subtle --almost to the point of being non-existent. If you're familiar with most kid's platformers, then you'll be intimately acquainted with Nemo's effects. There's nothing here you haven't heard, regardless of how nicely they are done. Music consists primarily of light, airy music that helps to give a certain peacefulness to the game's ocean environments. Things pick up during tense moments, such as when you're being chased by Bruce the shark. Though actor's voices from the movie are present during movie scenes, they aren't present in the game.