Green Hill

Green Hill is the first level in Sonic.exe The Glitch Chaos, as well as the second level in the first version of the game. You play as Sonic the Hedgehog in both versions, and later as Miles "Tails" Prower in Version 1.

Level
The level plays normally until you pass the goalpost. What happens next varies slightly depending on the version of the game, but in both, it ends with Sonic getting possessed.

In Version 1, Sonic encounters a garbled mess of pixels which quickly turn into a red eye, making Exester possess Sonic. In Version 2, Sonic encounters Error, who inserts Exester's soul into his body, killing Sonic in the process.

In Version 1, this is the first level that Tails goes through, although at night. Tails wonders why Sonic told him to come there. He says it'd better be important, then gets angry because it's always when he's busy, but then he comes across dead animals and becomes surprised and confused. He sees Exester in the distance and approaches them, thinking that they are Sonic, but then they open their eyes.