From a FAQ on Gamefaqs:
a) TOURIST-WEREWOLF EXPLOIT srch2a
This is an exploit that allows you to save some Tourists on levels in which
they would turn into Werewolves, even after the time limit has expired. In
particular, this exploit is useful in saving Victim number 9 on level 28,
because that particular Tourist Couple is much too far away from the start of
the level for you to have any hope of getting to them in addition to the other
two Tourist Couples present. However, for all its usefulness, this exploit may
be looked upon as cheating by some, and they will not want to use it.
While running Zombies, your Super NES machine has only a limited amount of its
resources dedicated to the Monsters that are present on-screen; in particular,
it only has the capacity to animate a certain number of sprites on the screen
at once. "Sprites" here means all objects that switch between frames of
animation, which includes Victims too. When a certain number of Monsters are
present, no more can be spawned until some have died, because otherwise the
Super NES would be unable to cope with all the work and would slow to running
the game at a snail's pace.
Tourist Couples are just one sprite, but each Werewolf is two sprites. More
importantly, if there are more than a certain number of enemies on screen, the
Werewolves are two enemies too many. So, if you have a certain number of
enemies following on close behind when you approach the Tourists, the machine
won't allow them to transform into more enemies, and you'll be able to collect
them. After collecting the Tourists, you are then free to kill the enemies
following you, as they have served their purpose - unless you want to collect
another Tourist Couple in this way, of course...
On level 28, for example, there is an area to the south of Victim #9 where
Vicious Zombies spawn at a reasonable rate. If you go there and wait around,
dodging the Zombies until there are five or six of them (but killing the
randomly spawning Werewolves that jump in), you will have a force of Monsters
that will prevent the Tourists (9) from transforming while they are in the
Super NES' memory. Shuffle along ahead of them, not allowing them to fall
behind and off the screen, and make your way north through the system of
passages to where the Tourists (9) stand. (The system might start working
slightly sluggishly when the Tourists come on-screen - this is normal.) You
will be able to collect them safely - after which you can get rid of the
Zombies chasing you, by shooting them all.
This tactic can also be used on, for example, level 48, to collect two
consecutive Tourist Couples (4 and 5) who are east across a stone walkway from
an area where Zombies spawn. An example of a level in which this approach is
unfeasible is level 17: here, the Tourists (9 and 10) are just past an area of
the level where a variety of enemies appear, and where other Victims can be
found. It is not a good idea to attempt to bring a group of Zombies through,
because they will try to kill the other Victims along the way, and because
there is nowhere nearby that can suitably be used to recruit them.
--------------------------------+++++++++++++++--------------------------------
b) CLEARING THE MACHINE'S MEMORY srch2b
Another limitation of the Super NES that may be exploited is the game's
inability to preserve the locations of most Monsters when they are too far away
from the player. For all but the most powerful, semi-boss-like Monsters (Crazy
Lumberjacks, Vampires, and Frankenstein's Monsters), the game will discard them
as soon as they are a certain distance off-screen. Even those three varieties
of Monster can do nothing of any consequence if the player is not nearby to
witness them doing it; that means that they can't kill Victims (and Lumberjacks
can't use their axes to demolish bits of the level, either).
This is convenient because sometimes when you arrive near a Victim, you'll see
that they are in danger, about to be killed by some Monster, and that you
definitely cannot do anything in time. What should be your reaction? Well,
perhaps you should consider just walking away - if you do that, then you could
easily manage to escape from the scene before the Zombie (or whatever it is)
makes the kill. If that happens, the Victim lives on, and you have another
chance. Remember, it's not over until you hear them scream!
