*Hidden Options*
- Weapon Select + Auto Reload -
How do you get to the hidden options menus?

Normal Difficulty level
Clear all stages. Then access the Game Settings menu. An extra item
[Special] appears, allowing you to select the following hidden options:

*Single Click Reload: Reload with a single click of the mouse.
*Random Mode: Opponents come out in random formation.
*Mirror Mode: The game screen appears as a mirror image of the original.
*Big Head Mode: Characters appear with humorously enlarged heads. 

Hard Difficulty level
Clear all stages. Then access the Game Settings menu. An extra item
[Special] appears, allowing you to select the following hidden options:

*Auto Reload: Weapons automatically reload when you use all the ammo.
*Weapon Select: Allows you to choose any of the special weapons during
 gameplay.
*Weapon Select (Special): A special version of the Weapon Select option. 

But don't expect to rack up high scores using these options. You get ranked
down for conduct unbecoming of an officer and not giving the badguys a fighting
chance.