<s>
Ninja	B-Application
Gaiden	I-Application
Shadow	I-Application
,	O
released	O
in	O
Japan	O
as	O
and	O
in	O
Europe	O
and	O
Australia	O
as	O
Shadow	B-Application
Warriors	I-Application
,	O
is	O
a	O
side-scrolling	O
action	B-Application
game	I-Application
released	O
for	O
the	O
Game	B-Device
Boy	I-Device
in	O
1991	B-Application
by	O
Tecmo	O
.	O
</s>
<s>
It	O
is	O
a	O
prequel	O
to	O
the	O
NES	O
Ninja	B-Application
Gaiden	I-Application
trilogy	O
.	O
</s>
<s>
Set	O
in	O
a	O
retro-futuristic	O
version	O
of	O
1985	O
,	O
three	O
years	O
before	O
the	O
events	O
of	O
the	O
first	O
Ninja	B-Application
Gaiden	I-Application
(	O
NES	O
)	O
,	O
the	O
player	O
controls	O
Ryu	O
Hayabusa	O
,	O
who	O
must	O
save	O
New	O
York	O
City	O
from	O
the	O
forces	O
of	O
Emperor	O
Garuda	O
,	O
a	O
servant	O
of	O
Jaquio	O
.	O
</s>
<s>
Ninja	B-Application
Gaiden	I-Application
Shadow	I-Application
features	O
simplified	O
play	O
mechanics	O
compared	O
to	O
those	O
used	O
in	O
the	O
NES	O
trilogy	O
.	O
</s>
<s>
While	O
Ryu	O
cannot	O
stick	O
to	O
or	O
climb	O
walls	O
like	O
in	O
the	O
NES	O
games	O
,	O
he	O
can	O
hang	O
onto	O
railings	O
and	O
move	O
underneath	O
them	O
like	O
in	O
Ninja	B-Application
Gaiden	I-Application
III	I-Application
:	I-Application
The	I-Application
Ancient	I-Application
Ship	I-Application
of	I-Application
Doom	I-Application
,	O
and	O
use	O
both	O
his	O
sword	O
attack	O
and	O
the	O
Fire	O
Wheel	O
art	O
while	O
hanging	O
onto	O
railings	O
.	O
</s>
<s>
Unique	O
to	O
this	O
installment	O
,	O
Ryu	O
is	O
equipped	O
with	O
a	O
grappling	B-Application
hook	I-Application
that	O
allows	O
him	O
to	O
latch	O
onto	O
hard-to-reach	O
railings	O
.	O
</s>
<s>
Ninja	B-Application
Gaiden	I-Application
Shadow	I-Application
was	O
originally	O
planned	O
to	O
be	O
a	O
Game	B-Device
Boy	I-Device
adaptation	O
of	O
the	O
NES	O
game	O
Shadow	B-Application
of	I-Application
the	I-Application
Ninja	I-Application
.	O
</s>
<s>
The	O
Nagoya	O
division	O
of	O
Natsume	O
,	O
which	O
developed	O
Shadow	B-Application
of	I-Application
the	I-Application
Ninja	I-Application
,	O
also	O
developed	O
Ninja	B-Application
Gaiden	I-Application
Shadow	I-Application
.	O
</s>
