Director’s Cut mode:
To unlock Director’s Cut mode, complete Story mode.

Dual Wield mode:
To unlock Dual Wield mode which allows one player to use two Wii-motes with one health bar, complete Director’s Cut mode.

Extra Mutants mode:
To unlock Extra Mutants mode, complete Story mode.

To unlock the Handcannon, complete Story mode.

To unlock the Minigun, complete Director’s cut mode.

Money Bonuses:
Complete the following tasks to earn the corresponding amounts of money:

Complete Level 1 in Story mode – $500
Complete Level 2 in Story mode – $1,000
Complete Level 3 in Story mode – $500
Complete Level 4 in Story mode – $500
Complete all levels in Story mode – $1,200
Complete Level 1 in Director’s Cut mode – $1,000
Complete Level 2 in Director’s Cut mode – $1,000
Get first place on high score screen – $1,000
Get last place on high score screen – $200
Get 70 total leg shots – $250
Get 50 total head shots – $200
Kill 50 Mutants in a level with your gun held sideways – $1,337
Level 1 score bonus – $5,000
Level 2 score bonus – $5,000
Level 3 score bonus – $5,000
Level 4 score bonus – $5,000
Level 5 score bonus – $5,000
Level 6 score bonus – $5,000
Level 7 score bonus – $5,000
Reach 70% accuracy – $400

All the achievements in the game can be seen under the Extra Contents menu (the extra videos, music, images, and 3D models).

Recommended weapon:
To consistently get a Goregasm combo, purchase and upgrade the autoshotgun to the maximum. A fully upgraded autoshotgun can one-shot most zombies.

Carney Boss Nigel and Sebastian strategy:
Note: This works best when you have an upgraded automatic shotgun. At first you will only have a gun. Shoot the small head as much as possible until you get to the part where the clowns start going crazy. There is a brain in the bottom corner of the box where the first clowns come out back to the Boss. Shoot the legs out from the under the clowns while flipping to make them crawl When they are on the ground, shoot the Boss.

The Lost Golden Brain hint:
The infamous lost golden brain changes location. Although this is not a glitch, the developers pretty much decided to make achieving everything close to impossible. The lost golden brain appears as just a speck in the corner of the pool room on the far right side. It can be found when you turn around after viewing the “experiments” and Isaac says “You’re into some sick s**t man.”

High score hint:
Tailor you high scores so you can easily rack in the bonus for “beating the high score”. If you cannot top your high score in a stage any more, you will not earn money for purchasing guns in the shop.

$1337 bonus hint:

Kill 50 mutants with your Wii remote held sideways in one level to earn an odd bonus of $1337.