Score
If you are interested in knowing your score throughout the game, enter this cheat after you insert credits at the title screen. The weapon has two buttons: the "trigger" and the "grenade" button. Press "trigger," "trigger," "grenade," "grenade," "trigger," "grenade," "trigger." If you enter the code correctly, you will hear a sound and your score will be displayed in the top corners of the screen while you are playing.
Defeating the Bosses
There are six boss creatures in this game, each with their own weak points.
You need to shoot the first boss needs while he is blocking his mouth. This will give you a higher score and kill him faster.
The second boss has a small spider head, in addition to his big head. Aim for the spider head; it will keep falling, but it will come back up.
The third boss is easy: Aim for the head accurately.
The fourth boss will take a grenade. When he is hanging from the building, throw the grenade, and it should kill him instantly.
The fifth boss flies around the screen and sprays purple sparks. Shoot the sparks when you can and aim for the head.
The final boss has a beating heart and creates monsters from ice. Shoot the ice monsters as fast as you can and aim for the boss's beating heart. Once you defeat him, a second version of him will appear. Defeat the second version the same way, being sure to kill the dragons that he creates. The dragons are weak in their mouths and their heads.
Different Paths
There are three secret paths that you can discover during the game. The first path is in the beginning level at the time when you are told to use the grenade. Instead of using the grenade, keep shooting the zombies until you see little red boxes behind them. Shoot the boxes, and the door you are standing in front of will shut, and you will be on a different path.
The second path is in the second level at the part when you are stuck behind a door and need to escape from the zombie. When it grabs you, do not shake the gun. Instead, wait until you hear a shout. You will be fighting the same zombies that you just fought minutes ago, and you will continue on a different path.
The last one is in the third level at the part with the slimy-mouth creatures. When you are next to the escalator, look for the door. When the monster grabs you, do not shake the gun, and he will let you go. Shoot the monster, and you have found the third alternative path.