Completing Story Mode
Completing story mode once unlocks a nifty hand cannon that you can use when playing a second game. The Hand Cannon is a rare weapon with a lot of blast power and produces satisfying results in killing enemies. You can also unlock the director's cut game mode by completing story mode. The director's cut features some never-before-seen content, and you must complete the mode if you want to finish the game at 100-percent game completion. Money earned and weapons cached in the director's cut are separate from those cached in the story mode.
Completing Director's Cut &Achievements
Completing the director's cut mode unlocks the minigun in your gun shop for both the story and the director's cut modes. The minigun is a powerful weapon that makes zombie killing easier, compared to other weapons in "Overkill." Check your Extra Contents menu to view the different lists of achievements and how you can accomplish them. By accomplishing one of these achievements, you earn the specific unlockable item for that task. The extra videos, images and music are also located in the achievement section.
Dual-Wield Mode
If the game seems too difficult to appreciate and you want to enjoy your Wii remote to the fullest, unlock the one-player, dual-wield mode. This mode enables the use of two remotes but retains only one lifebar. Unlock the dual-wield mode by completing the story mode to unlock the director's cut mode. Then finish the director's cut mode. You can now wield two remotes for easier kills and easier access to weapons. The game is much more fun and much more satisfying in the dual-wield mode, which you can use in both the director's cut and story modes.
The Lost Golden Brain
One of the more difficult achievements in "Overkill" is finding the Lost Golden Brain. Developers intended for it to change location and be almost impossible to accomplish. The Lost Golden Brain, however, has an actual location. It is a tiny speck in one of the corners of the pool room. The Lost Golden Brain is located on the far right side, just after you turn around and view the experiments. One of the characters, Isaac, will respond to the find by saying, "You're into some sick shit, man,"