You must have a 5 star rating in
Hardcore Mode on 2 Consecutive Scenes for these to work
Clown Heads - Left, Right, Left,
Right
Headshots - Up, Down, Right, Right
Headsots 2 - R Trigger, White, L
Trigger, L Trigger
Camheads - X, Black, L Trigger,
Down
Bin Bag - Black, Down, B, Left
Art For level - X, X, White, Down
Hoodie Designs - B, B, B, R
Trigger
Cerberus Designs - R Trigger, R
Trigger, X, L Trigger
Scarecrow - R Trigger, L Trigger,
White, L Trigger
Jury - R Trigger, R Trigger, Y, B
Clowns - White, White, L Trigger,
White
Smileys - Left, R Trigger, R
Trigger, Y
Piggys & Cash Toy - X, X, X, Down
Tramp - L Trigger, Y, Y, Y
Zoo Sniper - Down, Up, Left, Up
The Lost - White, Right, B, White
It was reported you have to have
3 stars on hardcore difficulty for these codes to work. 

Unlock All Weapons
You May need 3 stars on the bonus screen to get
this code to work??? At the main menu press
R, White, L, Black, Down,
Up, Left, Up.
Unlock Invincibility
You May need 3 stars on the bonus screen to get
this code to work??? At the main menu press
Down, Down, B, Up, X, Y, X, White, Up, Up, L, Y.
Unlock Helium Hunters
You May need 3 stars on the bonus screen to get
this code to work??? At the main menu press
R, R, Y, B, X, Black, L, Down.
Unlock Runner
You May need 3 stars on the bonus screen to get
this code to work??? At the main menu press
White, White, L, White,
Left, Right, Left, Right.
Unlock Silence
You May need 3 stars on the bonus screen to get
this code to work??? At the main menu press
R, L, White, L, Right,
Left, Left, Left.
Regenerate
You May need 3 stars on the bonus screen to get
this code to work??? At the main menu press
White, Right, B, White,
Black, Down, B, Left.
Unlock Super Punch
You May need 3 stars on the bonus screen to get
this code to work??? At the main menu press
L, Y, Y, Y, B, B, B, R.


Unlock Monkey Skin
You May need 3 stars on the bonus screen to get
this code to work??? At the main menu press
X, X, White, Down, Y, X,
B, Down.
Unlock Rabbit Skin
You May need 3 stars on the bonus screen to get
this code to work??? At the main menu press
Left, R, R, Y, R, R, X, L.

Unlock Piggsy Skin
You May need 3 stars on the bonus screen to get
this code to work??? At the main menu press
Up, Down, Left, Left, R,
White, L, L.