<s>
Contra	B-Application
4	I-Application
is	O
a	O
2D	O
action	O
game	O
published	O
by	O
Konami	O
Digital	O
Entertainment	O
in	O
the	O
United	O
States	O
and	O
developed	O
by	O
WayForward	O
Technologies	O
.	O
</s>
<s>
It	O
is	O
the	O
eleventh	O
overall	O
installment	O
of	O
the	O
Contra	B-Application
series	I-Application
,	O
and	O
was	O
released	O
in	O
North	O
America	O
on	O
November	O
13	O
,	O
2007	O
for	O
Nintendo	B-Device
DS	I-Device
.	O
</s>
<s>
Contra	B-Application
4	I-Application
serves	O
as	O
a	O
direct	O
sequel	O
to	O
1992	O
's	O
Contra	B-Application
III	I-Application
:	I-Application
The	I-Application
Alien	I-Application
Wars	I-Application
for	O
Super	B-Application
NES	I-Application
,	O
in	O
celebration	O
of	O
the	O
20th	O
anniversary	O
of	O
the	O
franchise	O
.	O
</s>
<s>
It	O
was	O
the	O
first	O
Contra	B-Application
game	O
released	O
on	O
a	O
portable	O
platform	O
since	O
1991	O
's	O
Operation	B-Application
C	I-Application
for	O
Game	B-Device
Boy	I-Device
.	O
</s>
<s>
The	O
plot	O
is	O
set	O
two	O
years	O
after	O
the	O
events	O
of	O
Contra	B-Application
III	I-Application
:	I-Application
The	I-Application
Alien	I-Application
Wars	I-Application
.	O
</s>
<s>
Bill	B-Application
Rizer	I-Application
and	I-Application
Lance	I-Application
Bean	I-Application
are	O
joined	O
by	O
Mad	O
Dog	O
and	O
Scorpion	O
as	O
they	O
travel	O
to	O
the	O
fictional	O
Galuga	O
archipelago	O
near	O
New	O
Zealand	O
(	O
the	O
setting	O
of	O
the	O
original	O
arcade	O
version	O
of	O
Contra	B-Application
.	O
)	O
</s>
<s>
In	O
the	O
North	O
American	O
versions	O
,	O
Black	O
Viper	O
was	O
originally	O
the	O
name	O
of	O
the	O
main	O
antagonist	O
in	O
Operation	B-Application
C	I-Application
,	O
while	O
"	O
Mad	O
Dog	O
"	O
and	O
"	O
Scorpion	O
"	O
were	O
the	O
codenames	O
of	O
Bill	O
and	O
Lance	O
.	O
</s>
<s>
Contra	B-Application
4	I-Application
is	O
based	O
on	O
the	O
same	O
2D	O
gameplay	O
featured	O
in	O
the	O
series	O
through	O
Contra	B-Application
III	I-Application
:	I-Application
The	I-Application
Alien	I-Application
Wars	I-Application
,	O
ignoring	O
many	O
of	O
the	O
game	O
mechanics	O
introduced	O
in	O
later	O
games	O
,	O
and	O
returning	O
to	O
the	O
old	O
method	O
of	O
picking	O
up	O
power-up	O
icons	O
to	O
obtain	O
new	O
weapons	O
.	O
</s>
<s>
The	O
play	O
controls	O
are	O
similar	O
to	O
Contra	B-Application
III	I-Application
,	O
including	O
the	O
ability	O
to	O
hold	O
two	O
weapons	O
in	O
the	O
player	O
's	O
inventory	O
.	O
</s>
<s>
The	O
action	O
spans	O
both	O
screens	O
of	O
the	O
Nintendo	B-Device
DS	I-Device
system	O
and	O
a	O
grappling	B-Application
hook	I-Application
can	O
be	O
used	O
by	O
the	O
player	O
's	O
character	O
to	O
latch	O
onto	O
railings	O
,	O
allowing	O
the	O
player	O
's	O
character	O
to	O
move	O
from	O
one	O
screen	O
to	O
the	O
other	O
.	O
</s>
<s>
Similarly	O
to	O
the	O
arcade	O
version	O
of	O
Super	B-Application
Contra	I-Application
,	O
the	O
player	O
can	O
pick	O
up	O
the	O
same	O
power-up	O
twice	O
,	O
giving	O
them	O
an	O
improved	O
version	O
of	O
the	O
same	O
weapon	O
.	O
</s>
<s>
In	O
addition	O
to	O
the	O
standard	O
side	O
view	O
stages	O
,	O
there	O
are	O
also	O
tunnel	O
stages	O
similar	O
to	O
the	O
two	O
"	O
3D	O
view	O
"	O
stages	O
from	O
the	O
original	O
Contra	B-Application
,	O
in	O
which	O
the	O
perspective	O
shifts	O
behind	O
the	O
character	O
's	O
back	O
.	O
</s>
<s>
Other	O
than	O
using	O
both	O
screens	O
,	O
Contra	B-Application
4	I-Application
makes	O
no	O
usage	O
of	O
the	O
DS	B-Device
 '	O
special	O
features	O
such	O
as	O
the	O
touchscreen	O
(	O
besides	O
navigating	O
the	O
main	O
menu	O
)	O
,	O
microphone	O
,	O
or	O
multiplayer	O
modes	O
.	O
</s>
<s>
The	O
stages	O
pay	O
frequent	O
homage	O
to	O
Contra	B-Application
,	O
Super	B-Application
Contra	I-Application
(	O
Super	B-Application
C	I-Application
on	O
the	O
NES	O
)	O
,	O
Operation	B-Application
C	I-Application
and	O
Contra	B-Application
III	I-Application
:	I-Application
The	I-Application
Alien	I-Application
Wars	I-Application
.	O
</s>
<s>
Normal	O
is	O
a	O
moderate	O
setting	O
described	O
to	O
be	O
"	O
as	O
difficult	O
as	O
the	O
original	O
Contra	B-Application
"	O
,	O
whereas	O
Hard	O
features	O
faster-moving	O
enemies	O
and	O
enemy	O
fire	O
,	O
with	O
fewer	O
lives	O
.	O
</s>
<s>
The	O
music	O
and	O
sound	O
effects	O
were	O
handled	O
by	O
famed	O
video	O
game	O
music	O
remixer	O
Jake	O
Kaufman	O
,	O
who	O
also	O
composed	O
for	O
Shantae	B-Device
and	O
founded	O
the	O
game	O
music	O
remix	O
site	O
VGMix	O
.	O
</s>
<s>
The	O
soundtrack	O
consists	O
of	O
a	O
few	O
arrangements	O
of	O
music	O
from	O
previous	O
Contra	B-Application
games	O
as	O
well	O
as	O
new	O
material	O
.	O
</s>
<s>
When	O
Arcade	O
Mode	O
is	O
played	O
on	O
the	O
Hard	O
setting	O
,	O
an	O
arranged	O
version	O
of	O
the	O
Jungle	O
theme	O
from	O
the	O
original	O
Contra	B-Application
is	O
played	O
instead	O
of	O
the	O
standard	O
stage	O
music	O
.	O
</s>
<s>
The	O
standard	O
Jungle	O
theme	O
is	O
actually	O
an	O
enhanced	O
version	O
of	O
a	O
"	O
Contra	B-Application
style	O
"	O
chiptune	O
song	O
previously	O
posted	O
on	O
Kaufman	O
's	O
website	O
,	O
called	O
"	O
Vile	O
Red	O
Falcon.	O
"	O
</s>
<s>
A	O
soundtrack	O
CD	O
was	O
announced	O
by	O
Konami	O
to	O
be	O
bundled	O
in	O
the	O
first	O
print	O
of	O
the	O
Japanese	O
release	O
of	O
Contra	B-Application
:	I-Application
Dual	I-Application
Spirits	I-Application
,	O
as	O
a	O
gift	O
for	O
preorders	O
through	O
the	O
KonamiStyle	O
shop	O
.	O
</s>
<s>
Contra	B-Application
4	I-Application
received	O
positive	O
reviews	O
from	O
critics	O
,	O
scoring	O
an	O
83	O
out	O
of	O
100	O
on	O
Metacritic	O
.	O
</s>
<s>
Contra	B-Application
4	I-Application
has	O
been	O
hailed	O
as	O
a	O
"	O
rebirth	O
"	O
of	O
the	O
franchise	O
,	O
and	O
was	O
praised	O
for	O
returning	O
to	O
its	O
roots	O
.	O
</s>
<s>
It	O
has	O
garnered	O
multiple	O
awards	O
including	O
IGN	O
's	O
"	O
Best	O
Action	O
Game	O
"	O
and	O
"	O
Best	O
Revival	O
"	O
of	O
2007	O
,	O
and	O
GameSpy	O
's	O
7th	O
best	O
DS	B-Device
game	O
of	O
2007	O
.	O
</s>
<s>
GamesRadar+	O
named	O
Contra	B-Application
4	I-Application
the	O
22nd	O
best	O
DS	B-Device
game	O
of	O
all	O
time	O
out	O
of	O
a	O
list	O
of	O
25	O
.	O
</s>
