<s>
Shadow	B-Application
World	I-Application
is	O
a	O
shoot	O
'	O
em	O
up	O
for	O
the	O
Atari	B-Device
8-bit	I-Device
family	I-Device
written	O
by	O
Mike	O
Potter	O
and	O
published	O
by	O
Synapse	O
Software	O
in	O
1983	B-Application
.	O
</s>
<s>
The	O
game	O
shares	O
elements	O
of	O
Potter	O
's	O
first	O
Atari	O
game	O
,	O
Protector	B-Application
,	O
itself	O
based	O
graphically	O
on	O
the	O
arcade	O
game	O
,	O
Defender	B-Application
.	O
</s>
<s>
Like	O
Defender	B-Application
,	O
the	O
action	O
is	O
primarily	O
side-scrolling	O
on	O
a	O
map	O
that	O
wraps	O
around	O
to	O
allow	O
continual	O
travel	O
to	O
the	O
left	O
or	O
right	O
.	O
</s>
<s>
Shadow	B-Application
World	I-Application
adds	O
a	O
limited	O
amount	O
of	O
vertical	O
scrolling	O
motion	O
as	O
well	O
.	O
</s>
<s>
Compared	O
to	O
Protector	B-Application
,	O
Shadow	B-Application
World	I-Application
has	O
much	O
more	O
action	O
with	O
significant	O
numbers	O
of	O
moving	O
objects	O
.	O
</s>
<s>
The	O
game	O
also	O
shares	O
elements	O
with	O
his	O
earlier	O
game	O
Nautilus	B-Application
,	O
notably	O
the	O
way	O
the	O
planet	O
is	O
laid	O
out	O
onscreen	O
and	O
the	O
way	O
the	O
player	O
has	O
to	O
destroy	O
certain	O
enemies	O
by	O
shooting	O
their	O
core	O
.	O
</s>
<s>
In	O
Shadow	B-Application
World	I-Application
,	O
the	O
players	O
are	O
in	O
charge	O
of	O
defending	O
the	O
planet	O
of	O
Jantor	O
,	O
which	O
is	O
under	O
attack	O
by	O
the	O
alien	O
Rigillians	O
who	O
are	O
attempting	O
to	O
steal	O
the	O
planet	O
's	O
supply	O
of	O
tricasmium	O
,	O
an	O
element	O
with	O
unique	O
multi-dimensional	O
properties	O
that	O
are	O
used	O
as	O
the	O
basis	O
of	O
all	O
modern	O
technology	O
.	O
</s>
<s>
The	O
player	O
's	O
fighters	O
,	O
shaped	O
either	O
like	O
the	O
fighter	O
from	O
Protector	B-Application
(	O
and	O
thus	O
Defender	B-Application
)	O
or	O
the	O
helicopter	O
from	O
Fort	B-Device
Apocalypse	I-Device
,	O
are	O
armed	O
with	O
a	O
gun	O
firing	O
to	O
the	O
left	O
and	O
right	O
,	O
as	O
well	O
as	O
three	O
smart	O
bombs	O
that	O
destroy	O
all	O
the	O
drones	O
that	O
are	O
on	O
the	O
screen	O
at	O
the	O
time	O
it	O
's	O
activated	O
.	O
</s>
<s>
Shadow	B-Application
World	I-Application
was	O
the	O
last	O
in	O
a	O
series	O
of	O
games	O
Potter	O
wrote	O
for	O
Synapse	O
in	O
a	O
one-year	O
period	O
between	O
November	O
1981	O
.	O
</s>
<s>
He	O
turned	O
to	O
the	O
nascent	O
IBM	B-Device
PC	I-Device
market	O
,	O
but	O
also	O
released	O
a	O
few	O
more	O
Atari	O
titles	O
with	O
other	O
labels	O
.	O
</s>
