<s>
is	O
a	O
2008	O
action	O
adventure	O
hack	B-Application
and	I-Application
slash	I-Application
game	O
developed	O
by	O
Team	O
Ninja	O
and	O
published	O
by	O
Microsoft	O
Game	O
Studios	O
for	O
the	B-Operating_System
Xbox	I-Operating_System
360	I-Operating_System
.	O
</s>
<s>
It	O
is	O
the	O
sequel	B-Language
to	O
the	O
2004	O
title	O
Ninja	B-Application
Gaiden	I-Application
,	O
making	O
it	O
the	O
second	O
3D	O
title	O
in	O
the	O
series	B-Application
of	I-Application
the	I-Application
same	I-Application
name	I-Application
,	O
and	O
was	O
released	O
worldwide	O
in	O
June	O
2008	O
.	O
</s>
<s>
A	O
reimagined	O
and	O
heavily	O
altered	O
version	O
,	O
titled	O
Ninja	B-Application
Gaiden	I-Application
Sigma	I-Application
2	I-Application
was	O
released	O
for	O
the	O
PlayStation	B-Operating_System
3	I-Operating_System
later	O
in	O
2009	O
,	O
and	O
was	O
published	O
by	O
Tecmo	O
Koei	O
,	O
followed	O
by	O
Ninja	B-Application
Gaiden	I-Application
Sigma	I-Application
2	I-Application
Plus	I-Application
for	O
the	O
PlayStation	B-Device
Vita	I-Device
in	O
2013	O
.	O
</s>
<s>
Shortly	O
before	O
its	O
announcement	O
,	O
on	O
September	O
11	O
,	O
2007	O
,	O
screenshots	O
of	O
the	O
game	O
were	O
accidentally	O
leaked	O
by	O
the	O
Japanese	O
Xbox	B-Operating_System
360	I-Operating_System
website	O
and	O
was	O
taken	O
down	O
hours	O
later	O
.	O
</s>
<s>
A	O
day	O
later	O
on	O
September	O
12	O
,	O
the	O
game	O
was	O
previewed	O
with	O
Microsoft	O
in	O
a	O
press	O
conference	O
of	O
Tokyo	O
Game	O
Show	O
2007	O
,	O
where	O
it	O
was	O
confirmed	O
to	O
exist	O
and	O
be	O
an	O
Xbox	B-Operating_System
360	I-Operating_System
exclusive	O
,	O
with	O
the	O
game	O
's	O
director	O
,	O
Tomonobu	O
Itagaki	O
,	O
being	O
stated	O
as	O
saying	O
,	O
"	O
Now	O
please	O
enjoy	O
the	O
world	O
's	O
best	O
action	O
game	O
,	O
running	O
on	O
the	O
world	O
's	O
best	O
hardware.	O
"	O
</s>
<s>
9	O
days	O
later	O
,	O
on	O
September	O
20	O
,	O
2007	O
,	O
Ninja	B-Application
Gaiden	I-Application
II	I-Application
was	O
officially	O
unveiled	O
to	O
the	O
public	O
,	O
with	O
its	O
first	O
trailer	O
at	O
the	O
Tokyo	O
Game	O
Show	O
2007	O
,	O
alongside	O
various	O
interviews	O
.	O
</s>
<s>
Ninja	B-Application
Gaiden	I-Application
II	I-Application
received	O
a	O
positive	O
critical	O
reception	O
,	O
with	O
praise	O
towards	O
its	O
difficulty	O
,	O
fast-paced	O
combat	O
and	O
level	O
of	O
violence	O
,	O
but	O
failed	O
to	O
recapture	O
the	O
acclaim	O
of	O
its	O
predecessor	O
,	O
and	O
was	O
criticized	O
for	O
not	O
being	O
an	O
improvement	O
over	O
its	O
predecessor	O
.	O
</s>
<s>
A	O
sequel	B-Language
,	O
Ninja	B-Application
Gaiden	I-Application
3	I-Application
,	O
was	O
released	O
on	O
March	O
20	O
,	O
2012	O
,	O
without	O
the	O
involvement	O
of	O
Tomonobu	O
Itagaki	O
.	O
</s>
<s>
Ninja	B-Application
Gaiden	I-Application
IIs	I-Application
new	O
combat	O
system	O
allows	O
the	O
player	O
character	O
Ryu	O
to	O
dismember	O
his	O
enemies	O
,	O
severing	O
their	O
limbs	O
and	O
tearing	O
their	O
bodies	O
apart	O
covering	O
his	O
weapon	O
and	O
everything	O
around	O
with	O
blood	O
.	O
</s>
<s>
Compared	O
to	O
Ninja	B-Application
Gaiden	I-Application
,	O
the	O
sequel	B-Language
contains	O
more	O
gore	O
and	O
graphic	O
violence	O
.	O
</s>
<s>
However	O
,	O
weapons	O
and	O
ninpo	O
from	O
the	O
original	O
Ninja	B-Application
Gaiden	I-Application
will	O
return	O
in	O
the	O
form	O
of	O
the	O
Art	O
of	O
the	O
Inferno	O
and	O
the	O
Vigoorian	O
Flail	O
.	O
</s>
<s>
One	O
year	O
after	O
Ninja	B-Application
Gaiden	I-Application
Black	O
,	O
master	O
blacksmith	O
Muramasa	O
is	O
setting	O
up	O
shop	O
in	O
Tokyo	O
,	O
Japan	O
.	O
</s>
<s>
The	O
plot	O
is	O
continued	O
in	O
Ninja	B-Application
Gaiden	I-Application
3	I-Application
and	O
its	O
expansion	O
Razor	O
's	O
Edge	O
.	O
</s>
<s>
Initial	O
screenshots	O
of	O
Ninja	B-Application
Gaiden	I-Application
II	I-Application
leaked	O
on	O
the	O
Japanese	O
official	O
Xbox	B-Operating_System
360	I-Operating_System
website	O
but	O
were	O
removed	O
within	O
a	O
matter	O
of	O
hours	O
on	O
September	O
11	O
,	O
2007	O
.	O
</s>
<s>
A	O
Day	O
later	O
,	O
on	O
September	O
12	O
,	O
2007	O
,	O
Microsoft	O
held	O
a	O
Press	O
Conference	O
to	O
the	O
Tokyo	O
Game	O
Show	O
2007	O
,	O
which	O
confirmed	O
the	O
game	O
's	O
existence	O
,	O
and	O
where	O
it	O
was	O
confirmed	O
as	O
an	O
Xbox	B-Operating_System
360	I-Operating_System
exclusive	O
.	O
</s>
<s>
8	O
days	O
later	O
,	O
on	O
September	O
20	O
,	O
Ninja	B-Application
Gaiden	I-Application
II	I-Application
was	O
officially	O
shown	O
at	O
the	O
Tokyo	O
Game	O
Show	O
2007	O
with	O
the	O
first	O
released	O
trailer	O
.	O
</s>
<s>
A	O
Ninja	B-Application
Gaiden	I-Application
II	I-Application
game	O
demo	O
was	O
released	O
on	O
the	O
Xbox	B-Application
Live	I-Application
in	O
Japan	O
on	O
May	O
31	O
,	O
2008	O
,	O
and	O
in	O
Europe	O
and	O
the	O
United	O
States	O
on	O
June	O
8	O
,	O
2008	O
.	O
</s>
<s>
An	O
altered	O
version	O
titled	O
Ninja	B-Application
Gaiden	I-Application
Σ2	I-Application
was	O
released	O
for	O
the	O
PlayStation	B-Operating_System
3	I-Operating_System
in	O
2009	O
and	O
for	O
the	O
PlayStation	B-Device
Vita	I-Device
in	O
2013	O
.	O
</s>
<s>
Ninja	B-Application
Gaiden	I-Application
II	I-Application
was	O
met	O
with	O
generally	O
positive	O
reviews	O
,	O
though	O
it	O
did	O
not	O
receive	O
the	O
acclaim	O
of	O
its	O
predecessor	O
.	O
</s>
<s>
GameSpot	O
nominated	O
it	O
for	O
the	O
award	O
of	O
'	O
Least	O
Improved	O
Sequel	B-Language
 '	O
in	O
its	O
2008	O
video	O
game	O
awards	O
.	O
</s>
<s>
On	O
August	O
28	O
,	O
2008	O
,	O
Ninja	B-Application
Gaiden	I-Application
II	I-Application
was	O
reported	O
as	O
having	O
sold	O
over	O
one	O
million	O
copies	O
.	O
</s>
