Sonic Heroes Is An Action Packed Adventure Game, Developed By SEGA In 2003.
It Has 4 Teams, 12 Heroes And 14 Stages!!

First Off Teams/Characters

Team Sonic: Sonic, Tails, Knuckles
Team Dark: Shadow/Rouge/Omega
Team Rose: Amy/Cream/Big The Cat
Team Chaotix: Espio/Vector/Charmy
LAST Story: Everyone. The Last Story Can Be Accessed By Collecting ALL 7 Chaos Emeralds, And Also Complete All Teams 100.

There Are 14 Stages, And 2 In Each Group, Because They Are The Same Ones:

1/2: Seaside Hill/Ocean Palace
3/4: Grand Metropolis/Power Plant
5/6: Casino Park/BINGO Highway
7/8: Rail Canyon/Bullet Station
9/10: Frog Forest/Lost Jungle
11/12: Hang Castle/Mystic Mansion
13/14: Egg Fleet/Final Fortress

Bosses, There are 8 In Total:
Egg Hawk - Stage 1/2
Team Battle: Team Sonic V Team Rose, Team Dark VS Team Chaotix - Stage 3/4
Robot Carnival: Stage 5/6
Egg Albatross: Stage 7/8
Another Team Battle: Team Sonic V Team Dark, Team Rose V Team Chaotix
Robot Storm: Stage 11/12
Egg Emperor: Stage 13/14

METAL OVERLORD: Final
Also, The Chaos Emeralds Can Be Achieved From The Following:
Green: Stage 1/2
Blue: Stage 3/4
Yellow: Stage 5/6
Grey: Stage 7/8
Cyan/Aqua: Stage 9/10
Purple: Stage 11/12
Red: Stage 13/14
After That You Can Fight The Final Boss, But You MUST Have Every Team Completed