Directors Cut Mode
Unlock director's cut mode by completing Story Mode. Money, weapons, etc. that you earn in story mode are NOT available in director's cut mode.
After you complete the Director's cut mode, the minigun is unlocked.
The list of all achievements is listed in the "Extra Contents" menu.
Unlock one-player "dual wield mode" where you can hold two remotes with one lifebar, by completing Director's Cut mode. This will be available in both Story and Director's Cut modes.
Extra Mutants Mode
Complete Story mode to unlock extra mutants in Story mode. Director's Cut already uses extra mutants.
Gangsta Grip Easter Egg
If you hold your wii-mote sideways through an entire level and you kill ore than 50 mutants, you get a "LEET" bonus of $1337.
You unlock the "Hand Cannon" in story mode and director's cut if you complete story