<s>
Alien	B-Application
Syndrome	I-Application
features	O
two	O
player	O
simultaneous	O
gameplay	O
and	O
pickups	O
which	O
assist	O
the	O
player	O
,	O
including	O
better	O
weapons	O
and	O
maps	O
of	O
the	O
current	O
level	O
.	O
</s>
<s>
In	O
1988	O
,	O
the	O
game	O
was	O
ported	O
to	O
the	O
Master	O
System	O
,	O
MSX	B-Operating_System
,	O
Amiga	B-Device
,	O
Atari	B-Device
ST	I-Device
,	O
Amstrad	B-Device
CPC	I-Device
,	O
Commodore	O
64	O
,	O
and	O
Famicom/Nintendo	O
Entertainment	O
System	O
(	O
published	O
by	O
Tengen	O
without	O
a	O
Nintendo	O
license	O
)	O
.	O
</s>
<s>
Later	O
,	O
the	O
game	O
was	O
ported	O
to	O
the	O
ZX	B-Operating_System
Spectrum	I-Operating_System
(	O
1989	O
)	O
,	O
Game	O
Gear	O
(	O
1992	O
)	O
,	O
and	O
X68000	B-Device
(	O
1992	O
)	O
.	O
</s>
<s>
In	O
Japan	O
,	O
Game	O
Machine	O
listed	O
Alien	B-Application
Syndrome	I-Application
on	O
their	O
May	O
15	O
,	O
1987	O
issue	O
as	O
being	O
the	O
third	O
most-successful	O
table	O
arcade	B-Application
unit	O
of	O
the	O
month	O
.	O
</s>
<s>
The	O
original	O
arcade	B-Application
version	O
of	O
the	O
game	O
was	O
reviewed	O
in	O
the	O
July	O
1987	O
issue	O
of	O
Computer	O
and	O
Video	O
Games	O
,	O
where	O
Clare	O
Edgeley	O
described	O
it	O
as	O
"	O
one	O
of	O
the	O
most	O
gripping	O
games	O
"	O
she	O
"	O
played	O
in	O
months	O
"	O
,	O
praising	O
the	O
Aliens-like	O
horror	O
atmosphere	O
,	O
chilling	O
sounds	O
,	O
special	O
effects	O
,	O
graphics	O
and	O
gameplay	O
.	O
</s>
<s>
The	O
game	O
was	O
also	O
converted	O
to	O
polygonal	B-General_Concept
graphics	O
for	O
the	O
PS2	B-Device
as	O
part	O
of	O
the	O
Sega	O
Ages	O
re-release	O
program	O
and	O
included	O
in	O
the	O
US	O
version	O
of	O
the	O
Sega	O
Classics	O
Collection	O
(	O
it	O
was	O
removed	O
from	O
the	O
European	O
version	O
to	O
receive	O
a	O
lower	O
age	O
certificate	O
)	O
.	O
</s>
<s>
This	O
version	O
has	O
updated	O
controls	O
,	O
adding	O
the	O
use	O
of	O
both	O
analog	O
sticks	O
,	O
similar	O
to	O
that	O
seen	O
in	O
Sheriff	B-Application
,	O
Robotron	B-Application
:	I-Application
2084	I-Application
and	O
Smash	B-Application
TV	I-Application
.	O
</s>
<s>
The	O
original	O
arcade	B-Application
game	O
was	O
also	O
included	O
as	O
an	O
unlockable	O
in	O
Sonic	B-Application
's	I-Application
Ultimate	I-Application
Genesis	I-Application
Collection	I-Application
.	O
</s>
<s>
A	O
sequel	O
of	O
the	O
same	O
name	O
,	O
Alien	B-Application
Syndrome	I-Application
,	O
was	O
released	O
for	O
Wii	B-Operating_System
and	O
PSP	B-Operating_System
on	O
July	O
24	O
,	O
2007	O
.	O
</s>
