<s>
Zarch	B-Application
(	O
also	O
known	O
under	O
its	O
ported	O
name	O
of	O
Virus	O
)	O
is	O
a	O
computer	O
game	O
developed	O
by	O
David	O
Braben	O
(	O
better	O
known	O
as	O
the	O
co-author	O
of	O
Elite	B-Application
)	O
in	O
1987	B-Application
,	O
for	O
the	O
release	O
of	O
the	O
Acorn	B-Device
Archimedes	I-Device
computer	O
.	O
</s>
<s>
Zarch	B-Application
started	O
off	O
as	O
a	O
demo	O
called	O
Lander	O
which	O
was	O
bundled	O
with	O
almost	O
all	O
releases	O
of	O
the	O
Acorn	B-Device
Archimedes	I-Device
.	O
</s>
<s>
In	O
1988	O
,	O
Zarch	B-Application
was	O
ported	O
(	O
under	O
the	O
new	O
name	O
,	O
Virus	O
)	O
to	O
the	O
Atari	B-Device
ST	I-Device
,	O
Amiga	B-Device
(	O
coded	O
by	O
David	O
Braben	O
)	O
,	O
and	O
IBM	B-Device
PC	I-Device
(	O
coded	O
by	O
Chris	O
Sawyer	O
)	O
.	O
</s>
<s>
It	O
was	O
later	O
ported	O
to	O
the	O
ZX	B-Operating_System
Spectrum	I-Operating_System
by	O
Steven	O
Dunn	O
.	O
</s>
<s>
when	O
it	O
reviewed	O
Zarch	B-Application
with	O
a	O
score	O
of	O
979	O
,	O
the	O
highest	O
rating	O
ACE	O
had	O
given	O
at	O
that	O
time	O
,	O
only	O
bettered	O
by	O
the	O
later	O
Amiga	B-Device
port	O
Virus	O
at	O
981	O
.	O
</s>
<s>
Virus	O
was	O
one	O
of	O
the	O
first	O
solid	O
3D	O
games	O
and	O
was	O
also	O
the	O
first	O
to	O
have	O
3D	O
lighting	O
effects	O
and	O
shadowing	O
,	O
although	O
these	O
are	O
less	O
sophisticated	O
than	O
those	O
of	O
Zarch	B-Application
.	O
</s>
<s>
The	O
plot	O
of	O
the	O
game	O
is	O
reminiscent	O
of	O
the	O
arcade	O
game	O
Defender	B-Application
,	O
in	O
that	O
the	O
player	O
,	O
piloting	O
a	O
lone	O
craft	O
with	O
limited	O
firepower	O
,	O
must	O
defend	O
a	O
finite	O
landscape	O
against	O
ever	O
increasing	O
waves	O
of	O
enemy	O
craft	O
.	O
</s>
<s>
In	O
Zarch	B-Application
,	O
the	O
landscape	O
is	O
being	O
invaded	O
by	O
aliens	O
who	O
are	O
spreading	O
a	O
virus	O
across	O
the	O
landscape	O
.	O
</s>
<s>
Zarch	B-Application
is	O
a	O
notoriously	O
difficult	O
game	O
for	O
beginners	O
.	O
</s>
<s>
No	O
powerups	O
are	O
available	O
in	O
the	O
game	O
,	O
although	O
the	O
player	O
has	O
a	O
limited	O
number	O
of	O
smart	O
missiles	O
,	O
and	O
smart	B-Device
bombs	I-Device
and	O
is	O
awarded	O
a	O
new	O
one	O
of	O
each	O
with	O
each	O
extra	O
life	O
.	O
</s>
<s>
Some	O
enemy	O
craft	O
are	O
so	O
agile	O
as	O
to	O
be	O
able	O
to	O
outmanoeuvre	O
the	O
missiles	O
,	O
and	O
the	O
smart	B-Device
bombs	I-Device
have	O
a	O
very	O
limited	O
range	O
.	O
</s>
<s>
In	O
the	O
top	O
left	O
of	O
the	O
screen	O
is	O
displayed	O
a	O
"	O
radar	B-Application
screen	O
"	O
,	O
which	O
provides	O
a	O
map	O
of	O
the	O
whole	O
landscape	O
,	O
with	O
the	O
position	O
of	O
the	O
lander	O
and	O
enemy	O
craft	O
marked	O
on	O
it	O
.	O
</s>
<s>
The	O
radar	B-Application
detection	O
is	O
provided	O
by	O
rotating	O
scanning-towers	O
which	O
are	O
evenly	O
spaced	O
across	O
the	O
landscape	O
;	O
accidental	O
destruction	O
of	O
these	O
results	O
in	O
loss	O
of	O
detection	O
in	O
that	O
area	O
,	O
and	O
black	O
squares	O
appear	O
on	O
the	O
map	O
.	O
</s>
<s>
It	O
additionally	O
does	O
not	O
appear	O
on	O
the	O
radar	B-Application
screen	O
.	O
</s>
<s>
In	O
advanced	O
levels	O
a	O
high-altitude	O
,	O
fast-moving	O
bomber	B-Application
craft	O
appears	O
,	O
dropping	O
packets	O
of	O
virus	O
particles	O
in	O
profusion	O
.	O
</s>
<s>
Braben	O
had	O
use	O
of	O
an	O
Acorn	O
A500	O
development	O
machine	O
for	O
two	O
weeks	O
in	O
January	O
1987	B-Application
.	O
</s>
<s>
He	O
had	O
been	O
working	O
on	O
3D	O
landscape	O
algorithms	O
on	O
the	O
BBC	B-Device
Micro	I-Device
and	O
then	O
wrote	O
Lander	O
using	O
ARM	B-Architecture
code	O
.	O
</s>
<s>
Lander	O
was	O
a	O
demo	O
version	O
of	O
Zarch	B-Application
bundled	O
with	O
new	O
Acorn	B-Device
Archimedes	I-Device
computers	O
.	O
</s>
<s>
Trees	O
,	O
buildings	O
and	O
enemies	O
are	O
drawn	O
in	O
filled	O
light-sourced	O
polygons	B-General_Concept
.	O
</s>
<s>
The	O
game	O
also	O
provides	O
particle	O
system	O
effects	O
to	O
depict	O
the	O
thrust	B-Application
from	O
the	O
lander	O
,	O
explosions	O
,	O
the	O
virus	O
spreading	O
over	O
the	O
landscape	O
,	O
and	O
assorted	O
other	O
phenomena	O
such	O
as	O
splashes	O
when	O
shots	O
strike	O
water	O
,	O
and	O
puffs	O
of	O
dust	O
when	O
they	O
strike	O
land	O
.	O
</s>
<s>
Scenery	O
(	O
trees	O
,	O
houses	O
,	O
radar	B-Application
)	O
.	O
</s>
<s>
The	O
hillside	O
landscape	O
is	O
generated	O
from	O
a	O
number	O
of	O
pseudorandom	B-Algorithm
sequence	I-Algorithm
sine	O
waves	O
.	O
</s>
<s>
The	O
game	O
was	O
voted	O
the	O
5th	O
best	O
game	O
of	O
all	O
time	O
in	O
a	O
1991	O
issue	O
of	O
Amiga	B-Device
Power	O
.	O
</s>
<s>
The	O
followup	O
to	O
Zarch	B-Application
was	O
a	O
game	O
using	O
the	O
same	O
landscape	O
engine	O
,	O
called	O
Conqueror	B-Application
.	O
</s>
<s>
It	O
was	O
coded	O
by	O
Jonathan	O
Griffiths	O
and	O
released	O
on	O
the	O
Archimedes	B-Device
,	O
PC	B-Device
,	O
Atari	B-Device
ST	I-Device
and	O
Amiga	B-Device
.	O
</s>
<s>
In	O
1998	O
,	O
ten	O
years	O
after	O
Zarch	B-Application
was	O
released	O
,	O
a	O
sequel	O
,	O
V2000	O
(	O
also	O
known	O
as	O
Virus	O
2000	O
)	O
,	O
was	O
released	O
for	O
the	O
PC	B-Device
and	O
PlayStation	B-Device
.	O
</s>
<s>
A	O
few	O
clones	O
based	O
on	O
Zarch	B-Application
have	O
also	O
been	O
created	O
,	O
including	O
a	O
version	O
for	O
Linux	B-Application
,	O
also	O
called	O
Zarch	B-Application
,	O
a	O
remake	O
for	O
Windows	O
(	O
written	O
in	O
Blitz	B-Language
BASIC	I-Language
)	O
called	O
Z-Virus	O
,	O
and	O
a	O
version	O
crossing	O
Zarch	B-Application
with	O
Pac-Man	B-Application
called	O
ZarchMan	O
.	O
</s>
<s>
The	O
Amiga	B-Device
game	O
Zeewolf	B-Application
(	O
1994	O
)	O
and	O
its	O
sequel	O
have	O
a	O
noticeably	O
similar	O
design	O
and	O
appearance	O
to	O
Zarch	B-Application
.	O
</s>
