Tails Story:
while sonics campaign was a much more straightforward adaption of the traditional 2d gameplay into a 3d environment, the tails levels are more... interesting. its a shorter campaign where the story is largely the same, just from tails perspective, and now the core gameplay is racing sonic in levels that are mostly identical to how they were in sonics campaign. its a neat little novelty but could have been done better. its not even all the sonic levels, and while tails does get his own sandboarding level, one where he doesnt race anyone, it just felt pointless. much like the bosses he fights. theyre almost all just "fight this character from the sonic campaign but without the homing attack" and the bosses were already a lowpoint in the game, or rather the boss fights against other characters you play as, anyway (though a couple of other bosses tails fights arent great either)
tails story does however make up for it all by the end with a great final race against eggman to see who can get to the nuke first, culminating into one of the best bosses in the game, the egg walker, as tails gets his moment in the spotlight as his own hero, independent of sonic (we dont talk about forces)
a charming little campaign