Green Hill Zone is the Sonic the Hedgehog stage. Based upon the classic and iconic Green Hill Zone, it has you fighting on a bit of a stage that has part of a loop on for you to dip into with a bridge to the left and more stage to the right. You can only do knock outs off of the left, right and upwards so you have to battle accordingly
There are various quirks and hazards in this level, first is the checkpoint. This checkpoint will move around the stage, however if you hit it with enough force, it will turn red and start spinning round, damaging anybody that it hits. The terrain around the loop is also fragile. If enough cumulative force is imposed upon it, it will temporarily break away, creating a hole in the level for you to try and knock people down into.
As a small Easter Egg, in the background, you will occassionally see Tails, Knuckle and Silver run past