Well, if someone who knows me really, really well, might think that i lost my mind, cause I really love Sonic, but honestly I don't think that this game is better than the one's that will come next on this list!!
I have a lot of reasons but I will just say the first one's that come to my mind:
1-The mechanics.
Sonic Heroes is a game where you can play with three characters simultaneously, but in my opinion that's not a good thing...
Everytime you move, you need to change character, it doesn't matter if it's to break a rock or to just fly through a cliff, you always need to change characters and that starts to feel boring and slow, so most of level you can't appreciate that much the speed sections cause your too worried for when you need to change the character
2-The Gameplay
Well, in this game you can play as four teams:
Team Sonic (with Sonic, Tails, &Knuckles)
Team Dark (with Shadow, Rouge and Omega)
Team Rose( with Amy, Cream and Big)
Team Chaotix( with Espio, Charmy and Vector)
Every team have its own story and different ways to play the game
In Team Sonic, you play the level like normal
With Team Dark, the level it's longer and a little bit harder
With Team Rose, the level it's easier
And with Team Chaotix, you play through the level but with missions
Of course that the game have some good things like the soundtrack, level design and characters models but one thing that just pissed me off as a kiddo was the rail physics!!
OMG, the rail physics...
I don't know how but in SA2, they did a great job at including the rail sections in the franchise (like Final Rush) but somehow, in this game they screwed everything!!!
But for conclusion, it's still a good game
I think that this soundtrack is what make me still love Sonic Heroes, honestly...