From Sonic Retro
Another zone that bites the bullet. In this prototype, Wood Zone is in a very early stage of development. Only the very beginning of the zone was implemented, and the ramps aren't even working properly. It's plausible that the zone was cut because Sega didn't have sufficient time to finish it.
Wood Zone plays Metropolis Zone music (#83 in our prototype), and the wooden passageway and conveyor belts do resemble certain elements in Metropolis Zone. Could Wood Zone be a "past" level of Metropolis?
Act 2 is completely empty.