While on the New Game Screen, hold L + R and press X, Y, B, Up, Right, A, B. 

10,000 Bullets Mode

While on the New Game Screen, hold L + R and press Up, Left, Down, Right, X.

Bang Bang Mode

While on the New Game Screen, hold L + R and press X, Y, B, X, Right.

Boomstick Mode

While on the New Game Screen, hold L + R and press Right, X (3x), B.

Chow Yun Jack Mode

While on the New Game Screen, hold L + R and press Y, X, Up (3x).

Fight Club Mode

While on the New Game Screen, hold L + R and press B, Left, X, Y.

Lazy Ass Mode

While on the New Game Screen, hold L + R and press Down, Left, Down, Y, Down.

One Hit Wonder Mode

While on the New Game Screen, hold L + R and press B, B, X, X, Right.

Sharpshooter Mode

While on the New Game Screen, hold L + R and press B (3x), Down, Right.

Time to Pay Mode

While on the New Game Screen, hold L + R and press B, B, X, X, Right.