Enter these codes in the various described locations to receive the desired effect.
Code                    Effect
Press Up, Up, Up, Left, Right, Left, Enter at the team menu or hero management screen.	100,000 Gold Coins
Press Up, Up, Down, Down, Left, Left, Left, Enter at the character select screen.	All characters
Press Up, Left, Left, Up, Right, Right, Up, Enter at the Review menu.	All Cinematics
Press Left, Right, Right, Left, Up, Up, Right, Enter at the Review menu.	All comic book covers
Press Down, Down, Down, Right, Right, Left, Down, Enter at the Review menu.	All Concept Art
Press Up, Down, Up, Down, Left, Right, Left, Right, Up, Down, Enter at the character select screen or the main menu.	All costumes
Press Up, Right, Left, Down, Up, Right, Left, Down, Enter at the simulator terminal screen where you choose a Comic Book mission.	All Courses
Press Left, Right, Left, Right, Up, Down, Up, Down, Left, Right, Enter at the character select screen or the main menu.	All powers
Press Up, Down, Right, Left, Up, Up, Down at the Review menu.	All Wallpapers
Press Left, Right, Right, Left, Up, Down, Down, Up during game play.	Filler
Press Up, Down, Up, Down, Up, Left, Down, Right, Enter during game play.	God Mode
Press Up, Left, Up, Left, Down, Right, Down, Right, Enter at the team menu.	Level 30 team
Press Up, Left, Up, Right, Down, Right during game play.	Super Speed
Press Left, Right, Down, Down, Right, Left, Enter during game play.	Touch of Death


Unlockables
Team Bonuses

Certain character combinations unlock special boosts.
Unlockable              How to Unlock
Agents of SHIELD        Captain America, Nick Fury, Spider-Woman, Wolverine
Agile Warriors : 10% Reduced Energy Cost	Spider-Man, Spider-Woman, Elektra, Deadpool
Air Force               Human Torch, Ms. Marvel, Storm, Thor
Alternate Identities    Ironman - War Machine, Ghost Rider – Western, Spider-Woman - Secret Wars, Ms. Marvel – Ventura, Thor - Beta Ray Bill
Assassins               Blade, Deadpool, Elektra, Wolverine
Avengers : +5% damage   Captain America, Thor, Iron Man, Spider-Woman, Ms. Marvel
Bad to the Bone         Blade, Ghost Rider, Luke Cage, Wolverine
Bruisers : +15 Striking Thing, Captain America, Luke Cage, Ms. Marvel
Classic Avengers        Black Panther, Captain America, Iron Man, Thor
Dark Past               Blade, Elektra, Ghost Rider, Spider-Woman
Defenders               Dr. Strange, Iceman, Luke Cage, Silver Surfer
Double Date             Black Panther, Invisible Woman, Mr. Fantastic, Storm
Fantastic Four : 20 Health per KO	Mr. Fantastic, Invisible Women, Human Torch, Thing
Femme Fatale : +5% Damage	Ms. Marvel, Storm, Invisible Woman, Elektra, Spider-Woman
Flashback               Iceman in Snowy Form, Captain America in WW2, Daredevil in Original, Ghost Rider in Original, Iron Man in Classic, Orig. Ms. Marvel, Classic Wolverine
Martial Artists         Black Panther, Captain America, Daredevil, Moon Knight, Nick Fury
Marvel Knights          Black Panther, Daredevil, Dr. Strange, Luke Cage, Spider-Man, Moon Knight
Marvel Royalty          Black Panther, Dr. Strange, Thor, Storm
Natural Forces : 5% Dmg inflicted as Health Gain	Thor, Strom, Human Torch, Ice Man
Natural Leaders         Captain America, Dr. Strange, Mr. Fantastic, Nick Fury, Storm
New Avengers : +5% All Resistances	Captain America, Luke Cage, Wolverine, Spider-Man, Spider-Woman
New Fantastic Four      Ghost Rider, Luke Cage, Spider-Man, Wolverine
Power Platoon : 20 Energy per KO	Silver Surfer, Iron Man, Ms. Marvel, Thor
Scorchers               Ghost Rider, Human Torch, Storm, Thor
Supernaturals           Blade, Dr. Strange, Ghost Rider, Thor
Weapons Specialists     Blade, Captain America, Deadpool, Elektra, Nick Fury
X-Men                   Colossus, Iceman, Storm, Wolverine


Unlock Daredevil and Silver Surfer

This code so far only works if you are playing with a gamepad. I haven't been able to get it right with just the keyboard.
Unlockable              How to Unlock
Unlock Dare Devil       Left, Left, Right, Right, Up, Down, Up, Down, Start Button
Unlock Silver Surfer    Down, Left, Left, Up, Right, Up, Down, Left, Start Button


Unlockables

Do the following tasks to unlock the following characters or modes.
Unlockable              How to Unlock
Black Panther           Collect Black Panther Action Figures throughout various acts
Blade                   Play Crane Game in Murder World
Daredevil               Collect Daredevil Action Figures throughout various acts
Dr. Strange             Rescue him from Mandrin in Act 1
Ghostrider              Rescue him from Mephisto in Act 2
Hard Mode               Complete the game on easy or normal mode
Nick Fury               Complete the game on easy or normal mode
Silver Surfer           Defeat Galactus