I have nothing bad to say about the graphics! In-game play was just plain pretty. The graphics for One Piece: Unlimited Adventure weren't mind-blowing or earth-shattering, or any other cliche or hyphenated words, but they were good! The water was fun, and had depth, the characters were colorful and crisp, and even the plants looked like I should be able to fluff their leaves. The cut scenes looked like they had 3D animated the anime series. It was almost like watching a Disney/Pixar movie... just really wordy and spastic. Basically, it is just really nice to play a game that doesn't have the graphics impeding the gameplay. I knew where I needed to go and the graphics aided in the game instead of holding me back.
The sound for this game is as spastic and insane as the anime. The in-game music is fun and upbeat. The best part was that it wasn't distracting; it flowed well with the gameplay. The most wonderful, skin-tingling, fuzzy kitten part of the sound? It was not repetitive! It didn't annoy me in the least. I haven't played a game -- short of Mario Galaxy -- in the last little bit that had nice music.