Head Shots
As you make your way through the levels, you'll encounter different ghoulish adversaries, each with their own attack. Practice your head shots and learn to rely on them--Most Zombies go down with a single shot to the cranium. (Remember that many Zombies can withstand three to four shots to the body or limbs.)

Center Enemies
With the Analog Pad (or Left Trigger) center your sights often: a good amount of the enemies appear near the center of the screen. Once you're proficient with your firearm, it's not a bad idea to speed up your gunsight, too (Options). This allows you to move your sight and track enemies faster.

Saving Hostages
The most important aspect of getting through the game is saving hostages - that's why you're here! It's also the quickest and easiest way through the game. The routes you follow are determined by which hostages you save (or fail to save), as well as other triggering actions, such as whether or not you shoot objects in the game, like keys or locks. Saving hostages gives you safer routes to follow, all leading the end of the level.

Secrets
1. Save all hostages: a bonus room will open in the last hallway before the Final Boss. 2. Score more than 70,000: another secret room opens in the same hallway, a special costume is your reward. 3. Score more than 100,000: get an infinite Credit power-up and an alternate ending. 4. To have the score appear onscreen during gameplay: press L, L, R, R, R, L, R, and then the START button on the title screen.

Boss 1 Judgment
Shooting the demon is difficult so find one spot onscreen (preferably near the center) and just fire, you'll hit him now and then. Your best chance to shoot him is right before the big guy strikes, as the demon floats up behind him, that's when he'll take the most damage. After the big guy falls, center your sights. The demon continues his attacks from the center of the screen. Keep you sights centered and keep blasting until he drops.

Boss 2 Hierophant
Take every possible shot at its exposed chest. Besides shooting it when it's chest is open, shoot at the top center of the screen (right through the health bar) when it makes a jumping attack. Shoot the Hierophant at the apex (highest point) of his jump.

Boss 3 Tower
At the beginning of this Boss battle, only one of the snake's heads will attack at once. Look for the residual sonic echoes from the attacking snake head as it emits a ghostly sound - this means he's about to attack! Shoot the mouth of the head that is about to attack. To kill the center head once it's slithering around the room, center your sights and aim a little above the sand or water This is the best spot to shoot towards, since the snake will cover the center of the screen as it strikes at you. Continue to shoot at the center of the screen until you've defeated the snake.

Boss 4 Strength
As Strength chases you around with a chainsaw, keep your guns trained on his head and keep shooting. Most of the time his head is protected, or obscured from view, so look closely for your opportunity to plant some slugs into him. If Strength is hiding off-screen, stay cool--He's about to jump out from behind an object! You'll only have seconds to shoot him in the head.

Boss 5 Magician
Shoot the exposed areas during Magician's first attacks. When he rushes at you, aim for a spot just left or right of the center of the screen (depending on the side of the screen he came from) and up a quarter of the way from the bottom. The boss's right shin (the weak point) passes over this area. In his last stage of attack, shoot constantly towards him and keep his projectiles from hitting you by shooting them out of the air.

Final Boss: Emperor
Shoot the red spot on the boss's transparent chest. As the other bosses appear in this battle, blast them in their weak points, as usual. When the Emperor is in his final stage of attack, continue to shoot at the red spot in the center of his chest.