- Aftermath

Learn how to finish Sonic the Hedgehog 3 & Knuckles, including the extended Mushroom Hill Zone, the Emerald Chamber, and the various endings based on Chaos Emerald collection.

After Tails airlifts Sonic to Mushroom Hill Zone (or flies there himself if playing as Tails), Act 1 features a new opening area. Proceed right to witness a cutscene of Knuckles hiding an item in a secret passage. After Knuckles departs, enter the passageway and jump into the Giant Ring to be transported to the Emerald Chamber of Hidden Palace Zone. Refer to the Special Stage section for more details.

Upon returning to Mushroom Hill Zone, exit the passageway and continue right to reach the starting area of Sonic & Knuckles alone. From this point, the levels are identical to Sonic & Knuckles. Consult the S&K Walkthrough for guidance on the latter half of the game. Any other discrepancies will be noted in that walkthrough.

With the options of playing as Sonic & Tails or Tails Alone, new routes become available. For instance, Tails can use his flight or airlift ability to reach previously inaccessible areas. The final Zone is The Doomsday for Sonic or Sonic & Tails, and Death Egg for Tails.

Endings

Sonic or Sonic & Tails

If all 7 Chaos/Super Emeralds were collected as Sonic, Super/Hyper Sonic descends with the Master Emerald. As Super/Hyper Sonic re-enters Mobius' atmosphere, Tails intercepts the Master Emerald in the Tornado. You revert to regular Sonic and land on the biplane. Sonic and Tails return the Master Emerald to Angel Island Zone, and as the island ascends, they depart. If all 7 Super Emeralds were acquired, Knuckles witnesses their departure.

If 0-6 Chaos Emeralds were collected as Sonic Alone or Sonic & Tails, Sonic falls from space, but the Master Emerald remains. As Sonic enters Mobius' atmosphere, Tails appears in the Tornado. You land on the biplane and return to the Floating Island, which remains at sea as Sonic and Tails depart.

Tails Alone

If all 7 Chaos/Super Emeralds were collected as Tails, Regular/Super Tails brings the Master Emerald down. As Regular/Super Tails enters Mobius' atmosphere, Sonic retrieves the Master Emerald in the Tornado. If you were Super Tails, you revert to Regular Tails and land on the biplane; Regular Tails lands directly on the Tornado. Sonic and Tails return the Master Emerald to Angel Island Zone, and as the island ascends, they depart. If all 7 Super Emeralds were acquired, Knuckles witnesses their departure.

Post-Credits Scenes

After the credits, a short scene plays based on your Chaos Emerald collection.

• 7 Chaos Emeralds: Shows the wreckage of the Death Egg with an EggRobo emerging (the one Knuckles fought).
• 7 Super Emeralds: Shows Sonic, Tails, and Knuckles in front of the Sonic 3 & Knuckles logo.
• 0-6 Chaos Emeralds: Shows Robotnik with the Master Emerald.