Sylvania Castle Zone
Sonic and Tails land the Tornado near the flooded ruins of an old castle. It seems that Dr. Eggman has hatched a new plan, this time involving the newly resurrected Metal Sonic. As you make your way through these ruins, keep an eye on the background to see hints of what Eggman is up to.
Music description: Act 1's theme is energetic, upbeat, and spunky, like the music for a starting zone should be. Act 2 is a bit slower-paced, with shades of Aquatic Ruins Zone, while Act 3 has a much more mystical feel.
Enemies: Bubbles (blue pufferfish) - Bubbles is present in every zone, and mostly serves as homing attack fodder. Be careful attacking the red ones though, since they have retractable spikes.
Mantis (grasshopper) - Mantis makes a return from Marble Garden Zone. He sits on the ground or ceiling and leaps at you when you approach.
Zoomer (kingfisher) - Zoomers hover above the water and will dive-bomb you. As long as you keep moving, they shouldn't be able to hit you. Be careful near the water's surface, though.
Chop-Chop (shark) - Chop-Chop returns from Aquatic Ruins Zone and just like before, he patrols underwater sections and will lunge at you. This time, he will also leap out of the water in some places, similar to Chopper or Masher. (NOTE: these badniks also appear in White Park Zone)
Fullboar (boar) - Fullboar appears in every zone except Oil Desert, and comes in several colors. Most of the time, they will just pace back and forth, but be careful of the more aggressive red ones.
Wheel Switches - These work just like the ones in Marble Garden Zone. Spin dash against the wheels to cause the scenery to shift, opening up a path.
Suspended platforms - You'll see a lot of these in Act 3. Some of them can move or rotate when hit with a homing attack.
Air pockets - These are essential to survive underwater. Breathe in large air bubbles to keep from drowning.
Spring pads - Some platforms float on the surface of the water and have springs underneath. Homing attack these to flip them over, then use the springs to reach higher areas.
Act 1: A New Frontier
Act 2: Sunken Ruins
Act 3: Moonlit Realm
Boss - Egg Serpentleaf
It looks as though Eggman is bringing back his Egg Totem machine from Sonic 2...but wait, what's this? Mechanical tentacles and a man-eating plant machine?! Wait for the machine to open up and expose Eggman's cockpit, then use Tails to fly to his level and attack him (you can't hit the underside of his ship, since it's protected by a force field). The tentacles will occasionally swat the ground, so keep your eyes on them and hit Eggman whenever the machine is opened. After a few hits, the tentacles will appear to strangle the machine and pump something into it. Now Eggman has a powerful laser weapon which he will sweep the screen with. Dodge the laser and use Tails to hit him a few more times and he will run for cover.