Metropolis Zone
Metropolis Zone's music uses different instruments from the final game, although the melody is basically the same. Wood Zone also uses this very same music, which makes some people think there's some uncanny relationship between the two zones.
This is the only zone that has 3 acts. Each act here is about 30% to 50% completed. The zone has no rings and is filled with navigational glitches, making turning on debug a must.
The most significant thing about this zone is the lift in act 3 that was cut from the final game.
Act 1
The pistons don't throw you very high, which means you'll get stuck at this spot without debug.
Thanks to the bugs in the game, these giants metals cannot crush you unless you go under them.
Some 3D rotating nets don't work either. You can fall right through it.
But this one does work. Looks like Sonic Team was testing the programming on one of them first.
Sonic just can't seem to die.
Act 2
Sonic and Tails can walk on fire.
It doesn't hurt one bit when totally submerged in fire either.
Act 3
Sonic standing on a diagonal lift, which did not make into the final version.
Another view of the lift.
Surprisingly, the conveyor belts do work, unlike those in Wood Zone.
Sonic standing on a platform that continuously moves to the right. When it reaches the end of the map, Sonic will be forced to fall to his death.