During a hands-off segment of the demo, we were shown a reworked version of Rooftop Run from Sonic Unleashed. Like Green Hill, it was reworked from scratch in both 2D and 3D, despite being a relatively recent addition to the series.
Confetti rains down from the skies like multi-coloured rain, and Robotnik's airship looms menacingly in the background. After racing across the quaint cityscape, classic Sonic scaled a Big Ben-esque tower and climbed up the clock hands.
A spin attack performed in the centre of the clock face caused it to swing open and collide with Robotnik's airship, enabling the hedgehog to climb on board. The outcome was entirely different when modern Sonic reached this juncture in his version of the stage.
Aided by the power of his boost metre, the contemporary character propelled himself to the highest point on tower and used it as a launch pad.