<s>
688	B-Application
Attack	I-Application
Sub	I-Application
is	O
a	O
submarine	O
simulator	O
video	O
game	O
designed	O
by	O
John	O
W	O
.	O
Ratcliff	O
and	O
Paul	O
Grace	O
and	O
published	O
in	O
1989	O
for	O
MS-DOS	B-Application
and	O
in	O
1990	O
for	O
Amiga	B-Device
by	O
Electronic	O
Arts	O
.	O
</s>
<s>
A	O
Sega	B-Operating_System
Genesis	I-Operating_System
version	O
developed	O
by	O
MicroProse	O
was	O
released	O
in	O
1991	O
by	O
Sega	O
.	O
</s>
<s>
The	O
player	O
takes	O
command	O
of	O
a	O
US	O
or	O
Soviet	O
nuclear-powered	O
attack	O
submarine	O
and	O
plays	O
ten	O
missions	O
ranging	O
from	O
into	O
either	O
Cold	B-Application
War	I-Application
scenarios	O
or	O
combat	O
missions	O
in	O
a	O
hypothetical	O
global	O
conflict	O
.	O
</s>
<s>
Two	O
people	O
can	O
play	O
against	O
each	O
other	O
over	O
a	O
modem	B-Application
(	O
or	O
null	O
modem	B-Application
cable	O
)	O
.	O
</s>
<s>
Ratcliff	O
and	O
Grace	O
later	O
developed	O
SSN-21	B-Application
Seawolf	I-Application
,	O
published	O
in	O
1994	O
.	O
</s>
<s>
The	O
magazine	O
praised	O
the	O
game	O
's	O
graphics	O
and	O
two-player	O
modem	B-Application
option	O
,	O
but	O
criticized	O
the	O
lack	O
of	O
more	O
than	O
ten	O
missions	O
.	O
</s>
<s>
Mike	O
Siggins	O
reviewed	O
688	B-Application
Attack	I-Application
Sub	I-Application
for	O
Games	O
International	O
magazine	O
,	O
and	O
gave	O
it	O
a	O
rating	O
of	O
7	O
out	O
of	O
10	O
,	O
and	O
stated	O
that	O
"	O
The	O
appeal	O
of	O
using	O
modern	O
weapons	O
soon	O
wears	O
off	O
and	O
one	O
is	O
left	O
with	O
only	O
the	O
different	O
situations	O
to	O
add	O
spice	O
.	O
</s>
