Best Sonic game after the Genesis years until Generations but that doesn't say anything.
In the game you can choose 4 teams. Sonic's team which is what I always pick. Shadow's team which is the same as Sonic's team but harder. Team Chaotix which makes you do strange activities like collecting 10 snails instead of getting from point A to point B. The last team is Amy's team. Worst. Team. Ever. My God this team sucks. Big the Cat is annoying as hell and has a strange frog fetish. The team is super easy to play as but they just suck so I avoid them at all costs.
The game-play of the game is different then the other Sonic games. You switch between 3 team mates with different powers. Sonic can run(duh), Knuckles can kick enemies asses and Tails can fly. However it's annoying when every time you switch to Tails he says 'Leave it to me!" in his annoying high voice. The game does even focus on the rings as much as the other games. Their just there. They don't feel important. You don't even lose all your rings when you're hit by enemies.
So Sonic Heros isn't the funniest game but it's not terrible. If you want to play a good Sonic game from the modern age play Sonic Generations and only Sonic Generations. Sonic Heros was Sega trying to do something different with the series but the result wasn't great.