<s>
SWIV	B-Application
is	O
a	O
vertically	O
scrolling	O
shooter	O
released	O
in	O
1991	O
for	O
the	O
Amiga	B-Device
,	O
Atari	B-Device
ST	I-Device
,	O
Commodore	O
64	O
,	O
MSX	B-Operating_System
,	O
ZX	B-Operating_System
Spectrum	I-Operating_System
,	O
and	O
Amstrad	B-Device
CPC	I-Device
computers	O
.	O
</s>
<s>
A	O
Game	B-Device
Boy	I-Device
Color	I-Device
conversation	O
was	O
published	O
in	O
2001	O
.	O
</s>
<s>
The	O
game	O
was	O
considered	O
a	O
spiritual	O
successor	O
to	O
Tecmo	O
arcade	O
game	O
Silkworm	B-Application
,	O
which	O
The	O
Sales	O
Curve	O
had	O
previously	O
converted	O
to	O
home	O
computer	O
formats	O
in	O
1989	O
.	O
</s>
<s>
The	O
game	O
's	O
heritage	O
is	O
evident	O
from	O
the	O
game	O
design	O
whereby	O
one	O
player	O
pilots	O
a	O
helicopter	B-Application
,	O
and	O
the	O
other	O
an	O
armoured	O
Jeep	O
.	O
</s>
<s>
SWIV	B-Application
is	O
not	O
an	O
official	O
sequel	O
,	O
as	O
noted	O
by	O
ex-Sales	O
Curve	O
producer	O
Dan	O
Marchant	O
:	O
"	O
SWIV	B-Application
was	O
n't	O
really	O
a	O
sequel	O
to	O
Silkworm	B-Application
,	O
but	O
it	O
was	O
certainly	O
inspired	O
by	O
it	O
and	O
several	O
other	O
shoot-	O
'	O
em-ups	O
that	O
we	O
had	O
played	O
and	O
loved.	O
"	O
</s>
<s>
In	O
the	O
game	O
's	O
Amiga	B-Device
manual	O
,	O
however	O
,	O
it	O
was	O
explained	O
that	O
"	O
SWIV	B-Application
"	O
was	O
both	O
an	O
acronym	O
for	O
"	O
Special	O
Weapons	O
Interdiction	O
Vehicle	O
"	O
and	O
also	O
short	O
for	O
"	O
Silkworm	B-Application
IV	O
"	O
(	O
even	O
though	O
there	O
was	O
not	O
a	O
Silkworm	B-Application
II	O
or	O
III	O
)	O
.	O
</s>
<s>
SWIV	B-Application
is	O
a	O
2D	O
vertically	O
scrolling	O
shooter	O
.	O
</s>
<s>
The	O
player	O
chooses	O
between	O
using	O
either	O
a	O
helicopter	B-Application
or	O
a	O
jeep	O
at	O
the	O
beginning	O
of	O
the	O
game	O
and	O
then	O
plays	O
in	O
their	O
chosen	O
vehicles	O
through	O
scrolling	O
levels	O
,	O
shooting	O
at	O
oncoming	O
enemies	O
.	O
</s>
<s>
On	O
release	O
SWIV	B-Application
was	O
met	O
with	O
positive	O
reviews	O
from	O
most	O
magazines	O
of	O
the	O
time	O
,	O
receiving	O
a	O
92%	O
from	O
Amiga	B-Device
Format	O
magazine	O
,	O
an	O
88%	O
from	O
Commodore	O
Format	O
(	O
C64	O
version	O
)	O
a	O
91%	O
from	O
Amiga	B-Device
Action	O
,	O
90%	O
from	O
Computer	O
and	O
Video	O
Games	O
,	O
and	O
a	O
90%	O
from	O
Your	O
Sinclair	O
.	O
</s>
<s>
It	O
was	O
ranked	O
the	O
27th	O
best	O
game	O
of	O
all	O
time	O
by	O
Amiga	B-Device
Power	O
.	O
</s>
<s>
A	O
sequel	O
was	O
published	O
for	O
the	O
Super	B-Application
Nintendo	I-Application
Entertainment	I-Application
System	I-Application
as	O
Super	B-Application
SWIV	I-Application
.	O
</s>
<s>
It	O
was	O
ported	O
to	O
the	O
Mega	B-Operating_System
Drive	I-Operating_System
as	O
Mega	B-Application
SWIV	I-Application
.	O
</s>
<s>
In	O
1997	O
SWIV	B-Application
3D	I-Application
was	O
released	O
,	O
with	O
3D	O
terrain	O
and	O
models	O
.	O
</s>
