Sonic Heroes is one of the best, if not THE best 3D Sonics EVER!
Instead of choosing one individual character, you choose a team, which consists of three characters. Each character is characterised by one of three labels depending on their skills/abilities-
Speed- (e.g. Sonic, Shadow)
Fly- (e.g. Tails, Rouge)
Power- (e.g. Knuckles, Omega)
You start of each level with the Speed character as the leader, and when you get to an area where you need to utilize a certain ability, you can switch to it and that character becomes the leader. In In other words, in a place with a lot of enemies, you would switch to the Power formation, an area with very little ground, flight. At first the idea of controlling 3 characters at once might seem a little complicated at first, but as the game progresses, you get used to it. So this is obviously a little more complicated than the others. But well done...
It still follows the idea of the traditional Sonic game, and really there's nothing else to it. So, if all you care about is pure Sega-mascot related platforming, (what a weird term...) with a reasonable challenge, this is one to check out. Plenty of great stages, challenges, and different level layouts for each team. I'd give this one a shot, but hey, that's what makes it my opinion.