First, unlock Debug mode by collecting any 16 Silver or Gold medals from the Blue Sphere special stages. Select Mania mode, highlight "No Save", choose the "Secrets" option, and enable Debug mode. Then, hold Square + X while "No Save" is highlighted in Mania mode to unlock the Level Select menu. This menu allows you to select any level (including special stages), Sound Test, and fight the secret final Boss without getting all Chaos Emeralds. You can even play as Tails and Knuckles against the secret final Boss. To switch characters, press Square while "Sound Test" is highlighted. To add Tails to Sonic, press Triangle while Sonic is shown under "Sound Test".All Chaos Emerald special stage locations
Search the indicated locations to get access to the special stages. Successfully complete the seven special stages to get all seven Chaos Emeralds. This path allows you to get all seven Chaos Emeralds and unlock Super Sonic before the end of Chemical Plant Zone - Act 1.
Collect all seven Chaos Emerald in the special stages to unlock Super Sonic.Secret final Boss and "True" ending
Collect all seven Chaos Emeralds with Sonic before completing Titanic Monarch - Act 2. After defeating the normal Boss of Titanic Monarch - Act 2, Sonic will be teleported to the true final Boss. Defeat that Boss to view the "True" ending.
Enter the "Cheat mode" code. At the level select screen, choose the final Boss option and play as Knuckles. Defeat the true final Boss as Knuckles to view a hidden ending. There will be a picture of Knuckles reading a book called "Sonic Mania & Knuckles" to the animals, with Sonic and Tails in the background. Alternatively, play &Knuckles mode with Knuckles.Medal unlockables
Earn the indicated number of medals by completing Blue Spheres special stages throughout the game to unlock the corresponding bonus:
- &Knuckles Mode: 11 medals
- Blue Spheres (play all 51 Blue Sphere stages): 32 medals
- D.A. Garden: 26 medals
- Debug Mode: 16 medals
- Insta-Shield: 6 medals
- Mean Bean: 21 medals
- Super Peel Out: 1 medal
While hanging onto any of the hook switches in Hydro City Zone, press Left(3), Right(3), Up(3) to have the gear boost pads in Hydro City play a voice clip each time you use them. If you entered the code correctly, you will hear a chime. Note: This code is a reference to Sonic And Knuckles; it is the level select code from that game.Alternate song in opening cutscene
Leave the game idle and let the intro cutscene play through once. The second time the cutscene plays, you will hear an alternate song.Infinite lives
When you enter Press Garden - Act 1, look for the first ink container you see (it spawns the hopping Badniks), stand next to it, and perform a spindash to kill the Badnik. Stop the spindash, let another Badnik come out, then kill it with the spindash. Repeat this to keep having the points stack up to give you free lives. Note: You cannot hold the spindash down -- you must release it in-between for another Badnik to spawn. Alternatively, you can use Super Sonic to stand there and do the same.Easy "Crate Expectations" trophy
While playing as Sonic in Press Garden Zone - Act 1, find the secret room next to the fire shield and destroy all the crates inside using the fire dash to get the "Crate Expectations" trophy.
Reach the Boss fight in Stardust Speedway Zone - Act 2 in less than one minute to get the "King Of Speed" trophy.Easy "Professional Hedgehog" trophy
Successfully complete Titanic Monarch Zone - Act 1 without getting hit to get the "Professional Hedgehog" trophy. Losing a shield still counts as a hit. Super Sonic is allowed.
Find the hidden submarine towards the end of the stage, at the bottom, in Oil Ocean Zone - Act 2 to get the "Secret Sub" trophy.
Find two item boxes at the end of any Act 1 to get the "That's A Two-fer" trophy. They are always in the same place. At the end of Green Hill Zone - Act 1, simply knock the Sonic/Dr. Eggman sign into the big sunflower on the right, and between the purple flowers on the left.Easy "The Password Is Special Stage" trophy
Reach the special stage ring hidden underneath the barrel in Mirage Saloon - Act 2. Once you reach the large barrel in the stage, simply push it to fall below and reach the hidden ring and get "The Password Is Special Stage" trophy. This can also be done in Time Attack mode.Easy "Window Shopping" trophy
Once you reach a new area towards the end of the Flying Battery Zone - Act 2 stage, there will be two windows with some coins behind them. It will be raining and thundering in this area. Jump through the second window to be blown into the first window to collect the coins and get the "Window Shopping" trophy.Trophies
Successfully complete one of the following tasks to get a trophy:
- No Way? No Way (Silver): Collect gold medallions in Blue Spheres Bonus stage.
- Full Medal Jacket (Silver): Collect silver medallions in Blue Spheres Bonus stage.
- Magnificent Seven (Silver): Collect all seven Chaos Emeralds.
- See You Next Game (Bronze): Achieve any ending.
- Superstar (Bronze): Spin the Star Post!
- That's a Two-fer (Bronze): Find the hidden item boxes at the end of the Zone.
- Now It Can't Hurt You Anymore (Bronze): What would happen if you cross a bridge with a fire shield?
- Triple Trouble (Bronze): Try for a 3 chain combo!
- The Most Famous Hedgehog in the World (Bronze): Have your photos taken in Studiopolis Zone.
- Window Shopping (Bronze): Let the wind take you through.
- Crate Expectations (Bronze): Wreak havoc at the propaganda factory.
- King of Speed (Bronze): Get through Stardust Speedway Zone as quickly as possible.
- Boat Enthusiast (Bronze): We really like boats.
- The Password is "Special Stage" (Bronze): Try pushing a barrel to see how far it goes.
- Secret Sub (Bronze): You might have to submerge to find it.
- Without a Trace (Bronze): Barrel through the lava, don't let anything stop you.
- Collect 'Em All (Bronze): Gotta gacha 'em all.
- Professional Hedgehog (Bronze): That elusive perfect run, only a professional can achieve.