<s>
Metal	B-Application
Gear	I-Application
Acid	I-Application
,	O
stylized	O
as	O
METAL	B-Application
GEAR	I-Application
AC	I-Application
!	I-Application
D	I-Application
,	O
is	O
a	O
turn-based	B-Application
collectible	O
card	O
tactical	O
RPG	O
video	O
game	O
developed	O
by	O
Konami	O
Computer	O
Entertainment	O
Japan	O
for	O
the	O
PlayStation	B-Operating_System
Portable	I-Operating_System
.	O
</s>
<s>
It	O
was	O
a	O
launch	O
title	O
for	O
the	O
PSP	B-Operating_System
,	O
though	O
a	O
Java	B-Language
ME	I-Language
version	O
for	O
mobile	O
phones	O
was	O
released	O
by	O
Glu	O
Mobile	O
in	O
2008	B-Application
titled	O
Metal	B-Application
Gear	I-Application
Acid	I-Application
Mobile	I-Application
.	O
</s>
<s>
Acid	O
focuses	O
on	O
turn-based	B-Application
tactics	I-Application
,	O
using	O
a	O
trading	O
card-based	O
system	O
to	O
control	O
the	O
main	O
character	O
's	O
movements	O
and	O
actions	O
.	O
</s>
<s>
The	O
game	O
allows	O
for	O
multiplayer	O
gameplay	O
by	O
wireless	O
ad-hoc	O
connections	O
of	O
two	O
PSPs	B-Operating_System
.	O
</s>
<s>
The	O
majority	O
of	O
the	O
cards	O
are	O
based	O
upon	O
elements	O
spanning	O
the	O
entire	O
Metal	B-Application
Gear	I-Application
series	I-Application
,	O
such	O
as	O
weaponry	O
,	O
characters	O
,	O
and	O
even	O
the	O
Metal	B-Application
Gear	I-Application
itself	O
.	O
</s>
<s>
Two	O
PSP	B-Operating_System
systems	O
running	O
Acid	O
can	O
link	O
wirelessly	O
,	O
allowing	O
players	O
to	O
face	O
each	O
other	O
in	O
a	O
"	O
sneak-off	O
"	O
.	O
</s>
<s>
Snake	O
is	O
led	O
to	O
believe	O
that	O
he	O
is	O
actually	O
Hans	O
Davis	O
,	O
a	O
researcher	O
involved	O
in	O
the	O
development	O
of	O
the	O
new	O
Metal	B-Application
Gear	I-Application
model	O
.	O
</s>
<s>
Teliko	B-Application
Friedman	I-Application
-	O
A	O
female	O
Japanese-American	O
member	O
of	O
the	O
Federal	O
Bureau	O
of	O
Investigation	O
's	O
Hostage	O
Rescue	O
Team	O
that	O
was	O
sent	O
to	O
the	O
Lobito	O
compound	O
prior	O
to	O
Snake	O
.	O
</s>
<s>
She	O
reappears	O
in	O
Metal	B-Application
Gear	I-Application
Solid	I-Application
:	I-Application
Portable	I-Application
Ops	I-Application
as	O
a	O
hidden	O
playable	O
character	O
.	O
</s>
<s>
Lt	O
.	O
Leone	O
-	O
The	O
leader	O
of	O
a	O
mercenary	B-Application
group	O
hired	O
by	O
an	O
anti-government	O
militia	O
in	O
the	O
Moloni	O
Republic	O
.	O
</s>
<s>
He	O
is	O
actually	O
William	O
L	O
.	O
Flemming	O
and	O
is	O
involved	O
in	O
the	O
development	O
of	O
the	O
new	O
Metal	B-Application
Gear	I-Application
.	O
</s>
<s>
The	O
first	O
meaning	O
refers	O
to	O
Acid	O
's	O
departure	O
from	O
the	O
previous	O
Metal	B-Application
Gear	I-Application
games	O
in	O
terms	O
of	O
style	O
,	O
which	O
is	O
an	O
analogue	O
to	O
acid	O
's	O
ability	O
to	O
dissolve	O
metal	O
.	O
</s>
<s>
The	O
third	O
is	O
stated	O
to	O
be	O
an	O
acronym	O
for	O
Active	O
Command	O
Intelligence	O
Duel	O
,	O
a	O
reference	O
to	O
the	O
game	O
's	O
mixture	O
of	O
turn-based	B-Application
tactics	I-Application
with	O
card-based	O
gameplay	O
.	O
</s>
<s>
The	O
soundtrack	O
was	O
released	O
on	O
December	O
21	O
,	O
2005	O
,	O
packaged	O
with	O
the	O
Metal	B-Application
Gear	I-Application
Acid	I-Application
2	I-Application
soundtrack	O
.	O
</s>
<s>
The	O
album	O
's	O
title	O
is	O
Metal	B-Application
Gear	I-Application
Acid	I-Application
1	O
and	O
2	O
Original	O
Soundtrack	O
,	O
the	O
first	O
disc	O
of	O
the	O
album	O
featuring	O
the	O
music	O
from	O
the	O
first	O
Metal	B-Application
Gear	I-Application
Acid	I-Application
title	O
.	O
</s>
<s>
Metal	B-Application
Gear	I-Application
Acid	I-Application
received	O
somewhat	O
positive	O
reviews	O
from	O
critics	O
,	O
citing	O
the	O
game	O
's	O
unique	O
mechanics	O
and	O
turn-based	B-Application
stealth	O
.	O
</s>
<s>
Acid	O
was	O
followed	O
by	O
a	O
sequel	O
for	O
the	O
PSP	B-Operating_System
,	O
Metal	B-Application
Gear	I-Application
Acid	I-Application
2	I-Application
,	O
which	O
released	O
the	O
following	O
year	O
.	O
</s>
<s>
A	O
mobile	O
phone	O
version	O
,	O
titled	O
Metal	B-Application
Gear	I-Application
Acid	I-Application
Mobile	I-Application
was	O
also	O
produced	O
.	O
</s>
