This one drags from the get-go. The cut scenes are maddeningly waffle-centric. but they can be skipped. However, what can't be skipped is the fetch-quests. Unlike Sonic Adventure 1, where the less interesting characters/playstyles were entirely optional; SA2 has them as mandatory. This leaves you having to guide the likes of Knuckles and Rouge to fragments of the Master Emerald. You're equipped with a radar to enlighten you when they're in the immediate vicinity, but otherwise, you're on your own. Now, fetch-quests are tiresome at the best of times, but Sega in their wisdom decided to make them randomized each turn. This meaning, no walkthrough can alleviate the tedium of having to trawl through an entire stage 'til your radar starts to bleep, as they'll be elsewhere each time you attempt the stage. The stages get bigger as the game goes on, and on one occasion there's a time limit. Keeping in mind that the average fetch-stage can take any amount of the time the game sees fit; this'll get especially gripesome.
Knuckles fetch-questing for reasons to keep playing this game.
The game has 30 stages, divided among six characters. Sonic/Shadow have typical, Adventure-decent Sonic gameplay, the aforementioned Knuckles/Rouge are the fetchers, and bizarrely, Tails/Eggman traverse mech-combat stages. The latter of which are actually fun, mostly, but almost simple to the point of redundany. Though, this still leaves you in the odd situation of playing a Sonic game, yet the majority of the game is based on playstyles not reflecting the one of the hedgehog whose name is on the cover (or download list, in this case).
I'll finish it, I always do with these things, but I don't get the impression I'll be feeling richer for the experience afterwards.