Green Hill Zone

Green Hill zone is the 1st level in the sonic the hedgehog series in the game sonic the hedgehog in 1991 this level is the most level appearances in sonic games

Sonic The Hedgehog
Sonic The Hedgehog is the 1st level of this or any sonic game

Sonic Adventure 2
In Sonic Adventure 2 Green Hill is an Unelectable action stage, it can be unlocked by getting all 180 emblems in the game, Eggman's robot in the level are chopper & Buzz Bomber