<s>
Call	B-Application
of	I-Application
Duty	I-Application
:	I-Application
World	I-Application
at	I-Application
War	I-Application
–	I-Application
Zombies	I-Application
(	O
also	O
known	O
as	O
simply	O
Call	B-Application
of	I-Application
Duty	I-Application
:	I-Application
Zombies	I-Application
)	O
is	O
a	O
first-person	O
shooter	O
video	O
game	O
developed	O
by	O
Ideaworks	O
Game	O
Studio	O
,	O
and	O
published	O
by	O
Activision	O
for	O
iOS	B-Application
.	O
</s>
<s>
It	O
is	O
a	O
spin-off	O
of	O
the	O
Call	B-Application
of	I-Application
Duty	I-Application
series	O
,	O
and	O
based	O
on	O
the	O
Zombies	O
mode	O
of	O
Call	B-Application
of	I-Application
Duty	I-Application
:	I-Application
World	I-Application
at	I-Application
War	I-Application
.	O
</s>
<s>
The	O
game	O
was	O
released	O
worldwide	O
for	O
iPhone	B-Device
on	O
November	O
16	O
,	O
2009	O
,	O
and	O
for	O
iPad	B-Device
on	O
April	O
1	O
,	O
2010	O
.	O
</s>
<s>
The	O
game	O
allows	O
for	O
multiplayer	O
cooperative	O
gameplay	O
locally	O
via	O
an	O
ad	O
hoc	O
Wi-Fi	O
or	O
Bluetooth	B-Protocol
network	O
,	O
or	O
globally	O
via	O
the	O
internet	O
.	O
</s>
<s>
A	O
sequel	O
to	O
the	O
game	O
,	O
Call	B-Application
of	I-Application
Duty	I-Application
:	I-Application
Black	I-Application
Ops	I-Application
–	I-Application
Zombies	I-Application
,	O
has	O
been	O
published	O
by	O
Activision	O
.	O
</s>
<s>
The	O
game	O
's	O
setting	O
originally	O
takes	O
place	O
in	O
a	O
German	O
bunker	O
(	O
Nacht	B-Application
der	I-Application
Untoten	I-Application
)	O
during	O
World	O
War	O
II	O
from	O
the	O
viewpoint	O
of	O
a	O
US	O
Marine	O
.	O
</s>
<s>
The	O
iPhone	B-Device
and	O
iPad	B-Device
versions	O
received	O
"	O
generally	O
favorable	O
reviews	O
"	O
according	O
to	O
the	O
review	B-Application
aggregation	I-Application
website	O
Metacritic	O
.	O
</s>
