(While looking at the score.) Otherwise I don't have the time to read the full review for reasons I'm not sharing over the internet. Some people, like me, read the conclusion and if I'm really interested in the game I'll read the full review.
One neat enhancement over the Dreamcast version is the GBA connectivity: using the GBA link cable, you're able to transfer Chao to the Tiny Chao Garden in Sonic Advance, Sonic Advance 2 and Sonic Pinball Party and earn extra items, although you can download a simplified version of the garden if you don't own any of these games. At first this appears largely throwaway stuff as the game never really keeps you in the loop in regards to how your Chao are doing, but the introduction of Chaos Drives adds a subtle layer of difference, as does the ability to create Light or Dark Chao, effectively tripling the number of potential Chao. Chao Garden returns from Sonic Adventure, in which you raise the tiny creatures and enter them into contests and fights. Going back to collect emblems, which are awarded for completing specific tasks within each level such as collecting a certain amount of rings or finishing a harder version of the level is somewhat enticing, as the reward for 100% collection is a re-imagined 3D version of Green Hill Zone. Once the Hero, Dark and Final stories are all polished off, players have a number of options available should they crave more. To use the word "handling" here seems far too generous needless to say, they don't control well at all, hampering any enjoyment these sections might have offered. Boss fights of varying quality also crop up throughout the game, in addition to some utterly terrible sections in which Tails or Rouge must drive a car along a narrow highway and reach the end before the time runs out.
Unfortunately, the Tails/Eggman levels are, for want of a better word, rubbish: the machine gun is beyond useless and each stage entails aiming at every enemy and destructible object while holding down the missile button until you reach the end. The Knuckles/Rouge segments are for the most part entertaining enough as you run, climb and glide around large wide-open areas, solving cryptic clues regarding the emerald pieces. However, when the camera does behave itself, around two thirds of Sonic Adventure 2's story mode is a lot of fun: the Sonic/Shadow stages all do a good job of adapting the series' trademark breakneck gameplay into a 3D space, introducing the grind mechanic that's become a staple in almost every Sonic game since. Instead of upgrading the camera system to make use of the GameCube controller's C-stick, camera control is still limited to rotating it with the shoulder buttons, which can lead to more untimely deaths than is generally tolerable. Regardless of which character you're playing, the camera often makes things difficult. Eggman's stages see each character piloting mechanised walkers armed with machine guns and lock-on missiles. In Knuckles and Rouge's levels you're tasked with hunting down pieces of the Master Emerald, with a hot or cold mechanic guiding you to each piece.
Sonic and Shadow's stages are fast-paced affairs in which you collect rings and defeat enemies in your goal to reach the end of the stage as quickly as possible. The goal is always to reach the end of the stage alive, with levels playing out in one of three ways. Luckily the story by no means gets in the way of the gameplay, which doesn't change the formula laid down in Sonic Adventure but rather refines it.