<s>
is	O
a	O
run	O
and	O
gun	O
video	O
game	O
for	O
the	O
Neo-Geo	B-Application
console/arcade	O
platform	O
created	O
by	O
Mega	O
Enterprise	O
along	O
with	O
Noise	O
Factory	O
.	O
</s>
<s>
It	O
was	O
released	O
in	O
2002	B-Application
for	O
the	O
Neo-Geo	B-Application
MVS	I-Application
arcade	O
platform	O
,	O
and	O
is	O
the	O
fourth	O
game	O
in	O
the	O
Metal	B-Application
Slug	I-Application
series	I-Application
.	O
</s>
<s>
Two	O
years	O
later	O
,	O
Playmore	O
published	O
Metal	B-Application
Slug	I-Application
4	I-Application
for	O
consoles	O
.	O
</s>
<s>
Metal	B-Application
Slug	I-Application
4	I-Application
retains	O
the	O
same	O
gameplay	O
as	O
previous	O
titles	O
,	O
with	O
the	O
addition	O
of	O
some	O
enemies	O
,	O
bosses	O
,	O
weapons	O
,	O
several	O
vehicles	O
and	O
a	O
bonus	O
combo	O
system	O
.	O
</s>
<s>
It	O
was	O
ported	O
to	O
Xbox	B-Application
and	O
PlayStation	B-Device
2	I-Device
as	O
a	O
stand-alone	O
game	O
in	O
Japan	O
and	O
Europe	O
,	O
and	O
along	O
with	O
Metal	B-Application
Slug	I-Application
5	I-Application
as	O
a	O
compilation	O
in	O
North	O
America	O
and	O
South	O
Korea	O
.	O
</s>
<s>
The	O
Nintendo	B-Application
Switch	I-Application
version	O
was	O
released	O
in	O
2018	O
.	O
</s>
<s>
One	O
year	O
after	O
the	O
events	O
of	O
Metal	B-Application
Slug	I-Application
3	I-Application
and	O
6	B-Application
,	O
the	O
world	O
is	O
under	O
the	O
threat	O
of	O
a	O
mysterious	O
and	O
deadly	O
cyber	O
virus	O
that	O
threatens	O
to	O
attack	O
and	O
destroy	O
any	O
nation	O
's	O
military	O
computer	O
system	O
.	O
</s>
<s>
In	O
Japan	O
,	O
Game	O
Machine	O
listed	O
Metal	B-Application
Slug	I-Application
4	I-Application
on	O
their	O
May	O
1	O
,	O
2002	B-Application
issue	O
as	O
being	O
the	O
second	O
most-successful	O
arcade	O
game	O
of	O
the	O
month	O
.	O
</s>
<s>
Metal	B-Application
Slug	I-Application
4	I-Application
was	O
mixed	O
to	O
positive	O
received	O
by	O
players	O
with	O
users	O
scores	O
of	O
7.8	O
for	O
PS2	B-Device
,	O
7.3	O
for	O
Xbox	B-Application
,	O
8.1	O
for	O
Neo	B-Application
Geo	I-Application
and	O
8.3	O
for	O
the	O
arcade	O
versions	O
,	O
while	O
Metacritic	O
and	O
Gamrankings	O
are	O
given	O
with	O
70.47	O
%	O
and	O
70	O
along	O
with	O
Metal	B-Application
Slug	I-Application
5	I-Application
as	O
compilation	O
for	O
both	O
PS2	B-Device
and	O
Xbox	B-Application
score	O
.	O
</s>
