Play as Bob:
To play as Bob, Mark's sick co-worker who passes out in "Outbreak", complete 
the "Outbreak" stage under any difficulty as Mark. Then, go to the collection menu 
and purchase costume number 12 for 4,000 points. Note: He will have Mark's 
storyline and voice.

Play as civilian:
To play as Man 1, 2, 3, 4, or 5, complete the "Decisions, Decisions" stage. Then, 
go to the collection menu and purchase costume number 30 for 10,000 points. 

Man 
1 and Man 2 have George's storyline and voice. Man 3 has David's storyline and 
voice. Man 4 has Mark's storyline and voice. Man 5 has Kevin's storyline and voice.

Play as Doctor Hursh:
Complete the "Hive" stage under the very hard difficulty setting as George. Then, 
go to the collection menu and buy costume 19 for 4,000 points. He will have 
George's storyline and voice.

Play as doctors:
To play as Doctor 1, 2, or 3, complete the "Hive" stage under the normal difficulty 
as any character. Then, go to the collection menu and buy costume 20 for 6,000 
points.All three of them have George's storyline and voice.

Play as scholars:
To play as scholars (scientists who gets shot in the head), complete the "Below 
Freezing Point" stage under the very hard difficulty setting. Then, go to the 
collection menu and buy costume 18 for 3,000 points. They both have George's 
storyline and voice.

Play as Frank:
To play as Frank you must complete the stage "Decisions, Decisions" under the 
hard difficulty setting. Once this is done, go to the "Collection" option at the main 
menu and choose "Costumes". You will need 8,000 points to unlock him. Note: 
When playing as Frank he will have Jim's storyline. 

Play as Monica:
To play as Monica from the stage "Below Freezing Point" you must first complete 
the stage as any character. Once done, go to the "Collection" option at the main 
menu and choose "Costumes". Her costume costs 5,000 points, Once unlocked you 
can play as Monica on any stage. Note: This is one of Alyssa's costumes; Monica 
will have Alyssa's voice effect. 

Play as Peter:
To play as Peter (George's friend), you must complete the stage "Decisions, 
Decisions" under the hard difficulty setting. Once this is done, go to 
the "Collection" option at the main menu and choose "Costumes". You must have 
5,000 points in order to unlock Peter as a playable charater. Note: Peter will have 
George's storyline.

Play as fire fighter or policeman:
To play as a fire fighter or policeman, complete the stages "Outbreak" and "Hell 
Fire" with any charter. Once done, go to the "Collection" option at the main menu 
and choose "Costumes". Both of those costumes cost 5,000 points. After unlocking 
them, they can be used on any stage. Note: They are Kevin and Mark's other 
costumes. When playing as either a fire fighter or policeman, they will have Kevin 
and Mark's storylines and voice effects.

Play as match stick men:
To play as match stick men you must complete all stages under easy, normal, 
hard, and very hard difficulty settings. You must also unlock all secrets in the 
game. Once done, go to the "Collection" option at the main menu and 
choose "Extras". Match stick men will cost 100,000 points to unlock. Note: Once 
the match stick men are unlocked, they will have Kevin's, David's, Jim's, Mark's, 
and George's storylines. 

Alternate Yoko costume:
To get an alternate costume for Yoko, play as Yoko complete the "Outbreak" stage 
under the normal difficulty setting. Once done, go to the "Collection" option at the 
main menu and choose "Costumes". Yoko's costume will cost 8,000 points. Once it 
is unlocked, you can play as Yoko before she changed into the person she is. 
Note: Yoko is the only character who has an alternate costume.

Hard mode:
Complete the "Decisions, Decisions" stage. You can now unlock hard mode for 
2,000 points. 

Very hard mode:
Complete all stages in hard mode. You can now unlock very hard mode for 3,000 
points. 

Solo mode:
Complete all stages in hard mode. You can now unlock very hard mode for 10,000 
points. 

Infinite ammo free mode:
Complete all stages with a 100% rating. You can now unlock infinite ammo free 
mode for 50,000 points. 

Secret FMV sequence:
On the stage "Below Freezing Point" there is a secret FMV sequence. To view it, 
you must do the following. After using the V-Jolt on the plant go up to level B-4 
(skip level B-5 for now). Once on B-4, go past the frozen Hunter and pick up the 
herb and pipe in the back. Then, go back to level B-6 (again skipping level B-5) 
and enter the keycodes into the main computer system. Make sure to enter the 
word "HOPE". Then, go to level B-5 and go through the vents. Be careful as a 
zombie will be here under the normal, hard, and very hard difficulty settings. Once 
through, go to the key panel, open the shutter, and enter the computer room. 
Then, enter your fingerprint into the computer. Finally, go back to level B-4 and go 
through the only open door. If done correctly, you will unlock the secret FMV 
sequence of your character getting attacked by the giant moth. Note: After the 
FMV sequence ends, you will be back in the computer room attached to the wall, 
and you must struggle to get out. This will cause your health to be in "Poison" 
status.

Defeating giant leech:
On The Hive level, the Boss will be a giant leech. To kill it easily, make it chase 
you back to the start, where you first get on the boat. Once there, hop out of the 
water and shoot him (if you have ammunition). If you do not have ammunition you 
can use the steel pipe, broom, crutch, or knife to kill him. If you are using the 
knife, you can either hop back in, stand in front of the giant leech, then stab; or 
you can stand out of the water and use the knife. When you stand outside of the 
water you will not be able to hit the giant leech until it lifts up its head. You must 
then stab quickly; you should be able to get two or three stabs. If you are in the 
water fighting the giant leech, you can get a few good swings at it, but be careful --
 it only shoots acid when it is stuck there. It also swings its head back and forth 
causing damage to your character. Note: Though this is a very easy way to kill the 
giant leech, you must also watch your partner's health. Your partner can die from 
the giant leech, and if that happens your partner will turn into a leechman. 

Defeating Hunters:
To kill Hunters easily, you can use a Magnum or do a team attack (this works 
offline and online). To use the team attack against the Hunters, have two people 
wait and have one as a decoy. For example, on the stage they appear on "Below 
Freezing Point", when you are in the West Passage area and the Hunter breaks 
free from the ice, it will stand there for a few seconds. Have two people wait 
around the corner and have one person run down the hall and back up towards the 
Hunter (not all the way in the doorway where the Hunter is located). Make enough 
room for him to pop out and around the corner. Once he is around the corner, 
have the two people who are waiting quickly run up and either start shooting or 
hitting it. The Hunter will have nowhere to go or have a chance to make an attack. 
This method works only for the stage "Below Freezing Point". Note: The only way 
you can get a Magnum is if you are playing as Yoko. Yoko gets the gun from a 
friend in the game, none of the other characters can get this gun.

Earn more points at the end of stages: 
To earn more points at the end of stages follow some of these steps:

No Damage Clear: To get a "No Damage Clear" do not get attacked by any kind of 
monster. If you come close to a monster, use your special attack (R1 + X) or ram 
the monster (R1 + Circle). When a monster is coming close to you, call for help 
(Right Analog-stick Left) and the CPU character will arrive to help. If done 
correctly you will get about 4,000 points. Note: This is not an easy task. It is 
recommended that you play the game a few times then trying for a "No Damage 
Clear". 

No Weapon Clear: To get points for a "No Weapon Clear", pass any weapons you 
find to the CPU. You cannot use any weapons/ You can pick them up and combine 
items for the CPU, but you can never use a weapon. You can use your special 
attack (R1 + X) and the characters will punch or kick the monster. You can also 
ram the monsters (R1 + Circle) . You also can use health items if needed for you 
or your CPU characters. Note: Only Kevin, David, Mark, and George can punch, 
kick, and tackle. 

Obtain all items: To get an even better score, obtain all items in the stage. You 
must collect files, useless items (such as diaries and test tubes), press buttons, 
etc. This will boost your points. Note: Collecting the items can clog up your 
inventory spaces. You can pass the items to your CPU characters to keep until the 
end of the stage. 

Obtain the "Daylight" virus: In the stage "Decisions, Decisions", collect an extra 
tube of "Daylight" virus and you will get a different ending and points. Note: When 
getting the extra "Daylight", do not use it. Keep it in your inventory for the 
different ending and points. 

Stopping your virus meter:
There are two ways to stop your virus meter from going up. The first way is to use 
the Anti-Virus Pill. This will stop the meter until you are attacked again. The other 
way is to use a Red Herb. This will stop the meter for a few minutes.

Using the hiding feature:
Try the following tricks to use the hiding feature to your advantage. Note: Do not 
to talk, look at your map, or open your menu screen, as this will blow your cover 
and the zombie or other monsters will cause damage to your character.

Hiding in lockers
You can hide from the monsters in lockers. For example, when in the "Outbreak" 
stage on the second floor and in the locker room, go to the last locker (next to the 
window). If you have a zombie chasing you and he happens to break down the 
door, hide in the locker. The zombie will look around, walk around in circles, then 
pound on the door to leave. Once he leaves, you can exit from the locker. Note: 
This works for all stages. 

Hiding under tables or beds
If a zombie is entering and there are no lockers, go under the table or bed. Your 
character will sit there, and the camera view will change so that you can see the 
zombie's feet. Stay under the table or bed until you see the zombie leave.