Successfully complete the Hero storyline to unlock the All Hail Shadow song.
All Of Me song (full version)
Successfully complete the Last Story to unlock the All Of Me song (full version).
Almost Dead song
Successfully complete the Dark storyline to unlock the Almost Dead song.
Character choices
In just about all of the stages you have three choices: to help the Dark side, yourself, or the Hero side whenever you have someone with you and it is not a Boss fight. To change the character you want with you, press Start. There will most likely be three selections: Dark, Neutral, and Hero. Press Left or Right to highlight a character or ring in the middle. Press X to select the highlighted character. That character will remain with you until your next run in with the other character. You can then simply press Start and do the process again. Note: You cannot select a Hero partner if there is an "X" over the Hero side. You cannot select a Dark partner if there is an "X" over the Dark side.
Another way to do this is to use the D-Pad on the controller during the game. Press Right for the Hero character, Left for the Dark character, and Down for the Neutral character.
Chosen One song
Successfully complete the Semi Hero storyline to unlock the Chosen One song.
Defeating Black Bull in Death Ruins level
Do not bother using the homing attack, as it is too hard to get to, and it is difficult to keep hitting him like that. Instead, defeat the two Black Arms soldiers and collect the guns from them. Then, go to the spring and use it. Move forward a bit so you do not start grinding the rails. Pass Black Bull in your jump, and rapidly shoot a little before you level with its eye. Repeat the strategy, and if you fill your Hero gauge, activate Chaos Control and finish him off. This is more effective and easier than to grind around him and shooting him every time around, which wastes ammunition on a lot of missed shots.
Defeating Black Bull in Lethal Highway level
At the start of the fight, run up to him and start using homing attacks on the Black Volts to get to his eye. When you hit him once, wait until Shadow comes out of spinning from the recoil and straightens up, then attack again. This will minimize your chances of diving to him and getting hurt instead of another homing attack. Continue this as long as possible. When he is in the middle of the street, there will be no Black Volts to bounce on. Instead, run directly under his head, then run away before he creates a shockwave under himself. By doing this, Black Bull will tilt his head down, making it an easy target. When he moves back, repeat. If you get a Gun from Black Arms soldiers, use it, but do not waste it. You will most likely fill your Hero gauge by then. Use it when he is easy to hit, then finish him off. He should not be too hard to defeat.
Destruction tasks easy!
After doing the last story on story mode, you'll have the shadow rifle... a black gun with a cool shape. It's super powerful, and transforms destruction of large vehicle tasks easy (ie destruction of evil kinevil spaceship or pathetic human leader 'president' escape pod.'.
Egg Vaccum
Finish the normal story line.
Expert mode
Get an "A" rank in all stages to unlock Expert mode.
Extra ammunition
Go to the stage were you have to kill the Chaos. There is a room near two GUN soldiers and a Chaos that has two weapon boxes in it. Break both boxes, then go in the room with the GUN soldiers. Go back and the boxes will be back. You can repeat this as many times as desired.
Fall through floor
On the stage where you first see Gloria on the space station you will fall through the floor after you get very far in the level. This happens in one of the hallways between rooms.
Heal Cannon
Finish full hero story line.
Independence Day reference in The Ark level
Finish The Ark level with the Dark objective. Then an intermission sequence will appear where the Black Arms fire the Eclipse Cannon and hit Central City, starting at the capital, which bears a striking resemblance to the famous Independence Day movie scene where the White house was destroyed.
Key bonuses
Collect all five hidden keys in the indicated level to unlock the corresponding bonus behind the five-keyed doors:
Air Fleet: Air Saucer
Black Comet: Two Turrets
Central City: Air Saucer
Circus Park: Extra shooting gallery
Cosmic Fall: Switch that makes ring trails to the end of the level
Cryptic Castle: Shortcut
Death Ruins: Warp Portal
Digital Circuit: Warp Portal
Final Haunt: Turrets
Glyphic Canyon: Black Arm's Vehicle
GUN Fortress: Military Vehicle
Iron Jungle: Tank Cannon
Lava Shelter: Air Saucer
Lethal Highway: Large GUN Cannon
Lost Impact: GUN Vehicle
Lost Impact: Armored Car
Mad Matrix: Alternate path to red terminal
Prison Island: Tank Cannon
Sky Troops: Black Arm's Vehicle
Space Gadget: Warp Hole
The ARK: Three extra lives
The Doom: Open cage to shortcut to the end of the level
The Last Way: Warp Portal
Westopolis: Armored Car
Last Story
Successfully complete every sixth stage in Story mode, defeat all Bosses at the end (all five Hero and all five Dark Bosses), and see all ten Hero and Dark story line endings to unlock the Last Story.
Library sequences
1: Punisment, Thy Name Is Ruin: Dark, Dark, Dark, Dark, Dark, Dark, Dark final Boss
2: Prologue To World Conquest: Dark, Dark, Dark, Dark, Dark, Dark, Hero ending
3: The March To A Darker World: Dark, Neutral, Dark, Neutral, Hero, Dark
5: Purification Via Ruination: Dark, Dark, Dark, Hero, Dark, Dark ending
6: Apogee Of Darkness: Dark, Dark, Dark, Hero, Dark, Hero ending
7: True Soldier Of Destruction: Dark, Dark, Dark, Hero, Neutral, Dark ending
8: Believe In Yourself: Dark, Dark, Dark, Hero, Neutral, Hero
11: Revenge At Last: Dark, Dark, Neutral, Dark, Dark, Dark ending
15: The Nightmare's Insulation: Dark, Dark, Neutral, Neutral, Dark, Dark ending
16: The Nightmare's Sublimation: Dark, Neutral, Neutral, Neutral, Dark, Hero
17: The Loner's Choice: Dark, Dark, Neutral, Neutral, Neutral, Dark
18: Subjugation IN BLACK: Dark, Neutral, Neutral, Neutral, Neutral, Neutral
27: The Cleansing of Darkness: Dark, Dark, Hero, Dark, Dark, Dark
45: The World's Demise: Dark, Hero, Dark, Dark, Dark, Dark ending
48: Vainglory or Abandonment?: Dark, Hero, Dark, Dark, Neutral, Hero ending
51: Controller from the Capsule: dark, hero, dark, neutral, neutral, dark
52: Beyond One's Own Power-: Dark, Hero. Dark, Neutral, Neutral, Good.
57: Transcendentalism: Dark, Hero, Dark, Hero, Neutral, Dark.
78: Power Of Love: Dark, Hero, Neutral, Hero, Hero, Hero
80: Walk My Way: Dark, Hero, Hero, Dark, Dark, Hero ending
91: The Rise and Fall Of The ARK: Dark, Hero, Hero, Hero, Dark, Dark
98: Severed Chains: Neutral, Dark, Dark, Dark, Hero, Hero.
102: Arriving At The Ego: Neutral, Dark, Dark, Hero, Neutral, Hero ending
105: Demise Wrought by Tragedy: Neutral, Dark, Neutral, Dark, Dark, Dark
111: Soldier Of Grief: Neutral, Dark, Neutral, Neutral, Neutral, Dark ending
112: Reclaimed Heart: Neutral, Dark, Neutral, Neutral, Neutral, Hero
120: Spawn Of The Devil: Neutral, Dark, Dark, Hero, Hero, Hero ending
121: Black Doom's Scheme: Neutral, Dark, Hero, Dark, Dark, Dark ending
135: A Vow For The Victims: Neutral, Dark, Hero, Hero, Neutral, Dark
144: One To Succeed A God: Neutral, Neutral, Dark, Neutral, Dark, Hero ending
145: Disappointed In Humanity: Neutral, Neutral, Dark, Neutral, Neutral, Dark
146: Faith Taken From Solitude: Neutral, Neutral, Dark, Neutral, Neutral, Neutral, Hero final Boss
153: Together With Maria-: Neutral, Neutral, Dark, Hero, Hero, Dark ending
154: The Tragedy's Conclusion: Neutral, Neutral, Neutral, Dark, Hero, Hero, Hero ending
155: The Day That Hope Died: Neutral, Neutral, Neutral, Dark, Dark, Dark
159: At Least, Be Like Shadow-: Neutral, Neutral, Neutral, Dark, Hero, Dark
160: Seeking A Silent Paradise: Neutral, Neutral, Neutral, Dark, Hero, Hero
161: The Lion's Awakening: Neutral, Neutral, Neutral, Neutral, Dark, Dark ending
162: Identity: Neutral, Neutral, Neutral, Neutral, Dark, Hero ending
163: An Android's Rebellion: Neutral, Neutral, Neutral, Neutral, Neutral, Dark
164: A New Empire's Begining: Neutral, Neutral, Neutral, Neutral, Neutral, Neutral,Hero final Boss
165: Bullets From Tears: Neutral, Neutral, Neutral, Neutral, Hero, Dark ending
166: Journey To Nihility: Neutral, Neutral, Neutral, Neutral, Hero, Hero
168: Dr. Eggman's Miscalculation: Neutral, Neutral, Neutral, Hero, Dark, Hero
170: Requiem For The Heavens: Neutral, Neutral, Neutral, Hero, Neutral, Hero ending
171: Sonic Dethroned: Neutral, Neutral, Neutral, Hero, Hero, Dark
175: Farewell To The Past: Neutral, Neutral, Hero, Dark, Neutral, Dark ending
182: Compensation For A Miracle: Neutral, Neutral, Hero, Neutral, Neutral, Neutral,Hero final Boss
191: Dark Soldier: Neutral, Hero, Dark, Dark, Neutral, Dark.
195: Birth Of The Dark Soldier: Neutral, Hero, Dark, Neutral, Dark, Dark
203: Perpetual Voyage: Neutral, Hero, Dark, Hero, Neutral, Dark
215: Wandering For Eternity: Neutral, Hero, Neutral, Neutral, Neutral, Dark ending
216: At Vagrancy's End: Neutral, Hero, Neutral, Neutral, Neutral, Hero ending
220: The Importance of Truth: Neutral, Hero, Neutral, Hero, Neutral, Hero ending
225: Solitary Journey: Neutral, Hero, Hero, Dark, Neutral, Dark.
228: I Shall Be The One To Judge: Neutral, Hero, Hero, Dark, Hero, Hero ending
229: Gone With The Darkness: Neutral, Hero, Hero, Neutral, Neutral, Dark
230: The Ultimate Choice: Neutral, Hero, Hero, Neutral, Dark, Hero
231: I Am The Strongest!: Neutral, Hero, Hero, Hero, Hero, Dark ending
232: Justice's Awakening: Neutral, Hero, Hero, Hero, Hero, Hero ending
259: A Heart Bound To The ARK: Hero, Dark, Neutral, Neutral, Hero, Dark ending
262: Steel Combat Boots: Hero, Dark, Neutral, Hero, Dark, Dark ending
263: Protector Of The Ashen Moon: Hero, Dark, Neutral, Hero, Neutral, Dark ending
266: I Know The Will Of Heaven: Hero, Dark, Neutral, Hero, Hero
275: The Reason You Were Born: Hero, Dark, Hero Neutral, Neutral, Dark
276: The Dark Part Of The Galaxy: Hero, Dark, Hero, Neutral, Neutral, Hero.
282: Beloved Memories: Hero, Dark, Hero, Hero, Hero, Hero
283: Birth Of A Devil: Hero, Hero, Dark, Dark, Dark, Dark
291: The Doctor's Lie: Hero, Hero, Dark, Neutral, Neutral, Dark
309: Funeral Procession In Space: Hero, Hero, Neutral, Neutral, Neutral, Dark
316: The One Who Maria Entrusted: Hero, Hero, Hero, Neutral, Hero, Hero
317: A.1's Enlightenment: Hero, Hero, Hero, Hero, Neutral, Dark, Dark ending
318: A Dying Empire's Cry: Hero, Hero, Hero, Dark, Dark, Hero
320: Tear-Soaked Hometown: Hero, Hero, Hero, Dark, Neutral, Hero ending.
321: Sparks On The Horizon: Hero, Hero, Hero, Dark, Hero, Dark ending
322: A Use For A Saved Life: Dark, Neutral, Dark, Hero, Dark
323: Coffin Of Memories: Hero, Neutral, Hero, Neutral, Dark, Dark
324: The Self-Imposed Seal: Hero, Hero, Hero, Hero, Neutral, Hero
325: Pretense in the Mirror: Hero, Hero, Hero, Hero, Hero, Dark
326: A Missive From 50 Years Ago: Hero, Hero, Hero, Hero, Hero, Hero, Hero final Boss
Never Turn Back song
Successfully complete the Dark storyline to unlock the Never Turn Back song.
NiGHTS reference in Lethal Highway level
At the start of Lethal Highway level, you should see a billboard to the right with an advertisement for a drink or something similar. If you continue watching it, it will switch to a picture of NiGHTS, which will then change to the NiGHTS title.
Omochao Gun
Finish the semi hero story line.
Samurai Blade
Successfully complete the Dark storyline to unlock the Samurai Blade.
Satellite Laser
Successfully complete the Semi Dark storyline to unlock the Satellite Laser.
Saving lives in Expert mode
In Expert mode, you must go through all of the levels one at a time without a break or mission, and on a harder difficulty. You are given five lives, any lives you pick up, but cannot continue. If you lose all your lives, you must start all the way back on the first level. However, if you find yourself in a dangerous position (for example, falling off a cliff), press Start before the game registers the loss of the life, then select "Quit". At the Expert mode menu, select "Resume". You will start at the beginning of the level you were on, but you will not lose that life and will resume with the total lives you had previously.
Shadow Rifle
Successfully complete the Last Story to unlock the Shadow Rifle.
Sonic Adventure 2 Battle References
Change the language to Japanese in options then go to 2P mode. Then go to the middle stage in level select and pick your characters. There should be music from Shadows first stage in Sonic Adventure 2 Battle.
The curse of lethal highway
On the level 'lethal highway'(level after doing hero on westopolis) rush through the level with sonic as your companion, but still try to attack evil kinevil spaceship, but rush. Hit the checkpoint at which sonic says 'I thought we lost em... etc etc' and approach the door. Occasionally, you'll see black, and if you try to walk past the door, then you'll fall. Move across using the magical 'floating' blobs.
Two player mode
Use controller two to play as the Hero characters, such as Sonic, Tails, Knuckles, etc. This does not work with Doom's Eye. It also works with Maria. Note: They cannot pick up guns.
Unlimited ammo
When your hero or dark gauge fills don't use special attack either if you have a weapon then you have unlimited ammo until the gauge is depleted.
Unlock More Weapons
Egg Vacuum - Clear story mode as neutral
Shadow Rifle - Clear Last Story mode
Omachao Gun - Clear story mode as slightly good
Satellite Laser - Clear story mode as bad
Samurai Sword - Clear story mode as evil
Healer Gun - Clear story mode as good
Yuji Naka reference
Sometimes the GUN soldiers will say odd things. One of the things that they say is "Mr. Yuji Naka is all right." Yuji Naka is the creator of the Sonic series.