from Ikachii at IGN
With that, the following differences have been confirmed:
-The PS2 version will have a new song for the opening movie, "Soshite Boku Ni Dekiru Koto." This will replace the "Starry Heavens" track in the GC version; however, both songs are by the same band, day after tomorrow. It is likely that the PS2 version as well will have this song removed should it go to the West.
-The PS2 will have a significant number of its cutscenes rendered in anime FMV. However, this is already cited as not being an "enhancement," but a means of compensate for the inability of the PS2 to perform everything in real-time using the game's graphics system. Two examples of events that are being replaced are the "Former Torietto Ruins" and "Rarebird" scenes (sorry for not knowing the proper English translatons for these)
-New events will be added in the PS2 version, including the following:
1) You can ride the jet stream coaster in the amusement park (Arutamira). Furthermore, you can choose who you want to ride it with.
2) More readable books on the religion of Maateru are scattered across the game map.
3) The casino in Arutamira now offers blackjack and other games that can be played. Earnings can be used to purchase not just garudo but EX Gems and also GRADE points
4) In the outdoor theater in Arutamira, there is an event in which Kuratos and Rifiru actually participate in a production due to a lack of performers.
5) In the snow village of Furanoru, there is a new event which explores a new side of Zeros (something triggered when Zeros lays his eyes on a father and his child near the ice statues)
6) Revisiting Parukomasuta after destroying the nearby human farm starts a new event regarding the creation of a new medal in celebration of the destruction of the farm.
7) Roido, Zeros, Regal, and Puresea each have one new special attack.
Roido - "Kaenrekkuu" (Air-Spin attack except the sword is flaming)
Zeros - "Dankuuken" (Spinning upwards tornado slice)
Regal "Retsuenshuu" (Spinning flame kick)
Puresea "Raishuuhougeki" (Overhead lighting ax strike)
8) Coretto and Kuratosu each have a new summon attack.
Coretto - "Grand Cross"
Kuratosu - "Shugohoujin" (literally, "protective magic square formation")
9) New "Compound Attacks" (fukugou tokugi) added to the PS2 version.
Roido + Regal - "Ryuukometsugajin" (circular lightning strike)
Shiina + Puresea - "Zanmagekkeika" (spinning sphere blade)
Coretto + Rifiru - "Fukuin" (literally, "Gospel")
9) The PS2 is to have new "Titles" (shougou) that each of the characters can achieve.
10) The PS2 version is cited to run at 30 frames a second due to hardware limitations (the GC version runs at 60). Apparently it was a necessary sacrifice to keep the quality of the graphics/images intact. Preliminary reviews of the PS2 version in Japan have cited the PS2 version as having a more "inorganic" feel relative to the GC original.