The vastly negative opinion Heroes gets really confuses me.
The gamecube (best version that anyone who wants to play the game should try) has a 72% on metacritic. Review sites weren't exactly praising the game but the general opinion from them seemed to be that the game was pretty decent and was a step in the right direction for the 3D outings since it was more focused and lighthearted.
I get the complaints (or at least some of them)... The game has a lot of little control issues and can act pretty funky at times. It's not as well put together in many ways as SA2 and it's not like that game is super-polished either.
But I dunno... I had a lot of fun playing it as a kid. I encountered very few hurdles from what I recall. Nothing really stumped me like, say, Crazy Gadget or Security Hall from SA2. Lives are plentiful, checkpoints are fairly close to one another, the combat is very basic and can be breezed through whenever you got your team at level 2 or 3... Even the Special Stages, as jank as they are, can be beaten by simply holding the boost button and literally not moving the stick at all (even on the last stage).
I just don't see what's so awful about the game. Could it have been better executed? Sure, but I like a lot of what they attempted here and I come back to Heroes far more than a number of other 3D entries in the franchise.
Best stage in that game was either Sky Fleet or Bullet Station imo. I love the grinding in Sonic games, though I recognize its not without flaws.
The grinding in Heroes is buggier than usual, since if you're not aligned with whatever rail you want to switch to, you can overshoot it. It's easy enough to prevent once you know it but I can understand why some have issues with it. Otherwise, it's a very fun stage with some kicking music. Hang Castle is my personal favorite due to the atmosphere and the huge shortcuts you can do.