Sonic Adventure was amazing. Bringing Sonic into 3D so well was a spectacular achievement. Sonic Adventure 2 wasn’t bad, just thoroughly mediocre and in many ways a step backwards from the original Sonic Adventure.
Sonic Heroes is an okay game. It’s certainly not an awful game. But it just doesn’t feel like a Sonic game. The levels are incredibly long (yet linear) and the team system and focus on battling enemies slows the game down to snail’s pace at times and more worryingly makes the whole experience inprecise and fiddly - a huge part of making Sonic work is the speed and fluidity, Sonic Adventure 2 managed to capture the speed and fluidity in the Sonic and Shadow levels at least (most of the time anyway, the somersault/lightspeed dash button sharing caused many problems, as did the rail mechanics).
Perhaps that’s why I enjoyed playing as Team Chaotix the most - because I was used to them functioning in teams from Chaotix’s partner system, they had varying missions, and I didn’t feel like I was being conned out of a Sonic game, I felt like I was playing a Team Chaotix game. Quite frankly I think that this SHOULD have been a purely Team Chaotix game as opposed to a Sonic game, at least then Sonic Team could actually take the team gameplay further rather then let it be tied down by traditional Sonic gameplay (a compromise, that as Heroes shows, doesn’t work very well).
Team Rose is easy mode and Team Dark is slightly harder mode. Very redundent.
The Special Stage access system doesn’t work well - you can only get a Chaos Emerald in the Special Stage for the second act of each zone, and as the Advance series has already shown, one emerald per zone simply does not work. It’s sad that nowadays the Chaos Emeralds have become something that you mostly have to go back for after completing the game. In the 16 and 8 bit games the goal was always to collect the Chaos Emeralds whilst playing through the game for the first time, not afterwards (although the opportunity was there in Sonic 3). You should be able to have multiple attempts at Chaos Emeralds whilst playing through the game normally.
The Special Stages themselves just plain suck. They’re fiddly and illogical and with a terrible physics system due to the analogue controls in a Sonic 2 style tube. It would’ve worked much better with just simple left and right, then you wouldn’t get slowed down to a halt when running on the sides.
The characters talk a lot during gameplay. This wouldn’t be a problem if there was an option to turn voices off, but alas, there is not. If you have the GameCube version (and Xbox too I believe) you can’t even switch between English and Japanese voices.
The bosses are cheap. There’re 3 mediocre Eggman bosses, one of which is just a rehash of the first, more grudge battles where you fight other teams (which sucked in both Adventure games, and they sucke here) and endurance battles, where you fight wave after wave of regular enemies. The penultimate boss is cool, but the Super Sonic section that follows it is fiddly, annoying and just not as cool as it should’ve been.
On the other hand, whilst Sonic Adventure 2 was visually repetitive, too realistic, dull and unappealing Sonic Heroes has some beautiful looking levels that are vibrant and fun, reminiscent of the Mega Drive games (the only one I didn’t like, was the casino level, which I felt offered little new and was too unrealistic for my tastes, it didn’t seem like a fantasy location like the other levels, just a mish-mash of platforming objects with a gambling theme). Unfortunately they don’t offer as much in-level variety as Sonic Adventure did (Twinkle Park for example, started out in a techno dodgems area, then went onto a roller coaster, then outside a general castle themed theme park and with Amy you could even go inside the castle, that’s in-level variety). The music is quite nice too, but again, not up to the standards of Sonic Adventure.