Cheats:
Get Air Instruments - Input Red + Red + Blue + Yellow + Green + Green + Green + Yellow
Always Get Drum Fill - Input Red + Red + Red + Blue + Blue + Green + Green + Yellow
Always Get Slide - Input Green + Green + Red + Red + Yellow + Red + Yellow + Blue
Get Auto Kick - Input Yellow + Green + Red + Blue + Blue + Blue + Blue + Red
Get Black Highway - Input Yellow + Red + Green + Red + Green + Red + Red + Blue
Get Flame Color - Input Green + Red + Green + Blue + Red + Red + Yellow + Blue
Get Gem Color - Input Blue + Red + Red + Green + Red + Green + Red + Yellow
Get Hyperspeed (all instruments) - Input Green + Blue + Red + Yellow + Yellow + Red + Green + Green
Get Invisible Rocker - Input Green + Red + Yellow + Yellow + Yellow + Blue + Blue + Green
Get Performance Mode - Input Yellow + Yellow + Blue + Red + Blue + Green
Get Star Color - Input Red + Red + Yellow + Red + Blue + Red + Red + Blue
Get Vocal Fireball - Input Red + Green + Green + Yellow + Blue + Green + Yellow + Green
Get Additional Line 6 effects (Music Studio) - Input Green, Red, Yellow, Blue, Red, Yellow, Blue, Green

Get Metallica Costumes:
At the cheat menu + input: Green + Red + Yellow + Blue + Blue + Yellow + Red + Green

Get Motorhead Lemmy:
Complete Ace of Spades in career mode.

Get Other Costumes:
Get Classic James - Win 150 Stars Vocals.
Get Classic Lars - Win 150 Stars Drums.
Get Classic Kirk - Win 150 Stars Guitar.
Get Classic Robert - Win 150 Stars Bass.
Get Zombie James - Win 200 Stars Vocals.
Get Zombie Lars - Win 200 Stars Drums.
Get Zombie Kirk - Win 200 Stars Guitar.
Get Zombie Robert - Win 200 Stars Bass.

Get Characters:
Get Kirk Hammett - Acquire 100 stars in Guitar Career.
Get James Hetfield - Acquire 100 stars in Vocalist Career.
Get Lars Ulrich - Acquire 100 stars in Drum Career.
Get Robert Trujillo - Acquire 100 stars in Bass Career.
Get King Diamond - Acquire King Diamond's "Evil".