(Basically this is a scenario like the game)

Scenario 1. You were walking down Green Hill but known as Hill and heard the Reversed Green Hill music. You soon see dead animals and Tails.exe along with Sonic.exe and you make a run for it

Scenario 2. You were in Green Hill and looked behind you to see Sonic.exe chasing you and you run faster to escape him

Scenario 3. Make it up