In thier review they say, "If the first Kingdom Hearts was a crazy experiment, then the sequel is the final product, refined and polished in dozens of small-but-important ways. One of the most obvious improvements is the game's massively higher budget; though the first looked nice, Kingdom Hearts II is one of the best looking games the PS2 has ever -- or will ever -- see. From photorealistic models to "I can't believe it's not PS3" massive battles, the game convinces the aging PS2 hardware to do things that seem nearly impossible."
Kingdom Hearts 2