<s>
Earth	O
's	O
response	O
is	O
Operation	O
Viper	B-Application
Phase	I-Application
1	I-Application
:	O
to	O
combat	O
the	O
rebels	O
using	O
advanced	O
space	O
fighters	O
built	O
from	O
downed	O
enemy	O
ships	O
.	O
</s>
<s>
A	O
new	O
version	O
of	O
Viper	B-Application
Phase	I-Application
1	I-Application
was	O
released	O
with	O
gameplay	O
changes	O
.	O
</s>
<s>
The	O
new	O
version	O
is	O
known	O
as	O
Viper	B-Application
Phase	I-Application
1	I-Application
:	O
USA	O
in	O
the	O
United	O
States	O
.	O
</s>
<s>
Secondary	O
weapons	O
:	O
The	O
original	O
version	O
of	O
Viper	B-Application
Phase	I-Application
1	I-Application
has	O
limited	O
ammunition	O
in	O
the	O
secondary	O
weapons	O
.	O
</s>
<s>
The	O
Raiden	B-Application
Fighters	I-Application
series	O
uses	O
this	O
bomb	O
deploy	O
time	O
of	O
the	O
new	O
version	O
as	O
part	O
of	O
the	O
Judge	O
Spear	O
's	O
guest	O
appearance	O
.	O
</s>
<s>
Medals	O
:	O
Taking	O
a	O
cue	O
from	O
the	O
mechanics	O
of	O
Raiden	B-Application
DX	I-Application
,	O
medals	O
stop	O
shimmering	O
for	O
a	O
brief	O
moment	O
,	O
during	O
which	O
they	O
award	O
more	O
points	O
when	O
collected	O
.	O
</s>
<s>
There	O
are	O
six	O
types	O
of	O
powerups	O
in	O
Viper	B-Application
Phase	I-Application
1	I-Application
.	O
</s>
<s>
This	O
weapon	O
is	O
included	O
in	O
the	O
Raiden	B-Application
Fighters	I-Application
series	O
along	O
with	O
the	O
ship	O
(	O
later	O
named	O
Judge	O
Spear	O
)	O
in	O
a	O
guest	O
appearance	O
.	O
</s>
<s>
The	O
soundtrack	O
of	O
Viper	B-Application
Phase	I-Application
1	I-Application
was	O
composed	O
by	O
Go	O
Sato	O
.	O
</s>
<s>
The	O
soundtrack	O
is	O
available	O
as	O
an	O
unlockable	O
in	O
the	O
Japanese-only	O
release	O
of	O
Raiden	B-Application
DX	I-Application
for	O
the	O
PlayStation	B-Device
.	O
</s>
<s>
When	O
unlocked	O
,	O
players	O
have	O
the	O
option	O
of	O
changing	O
the	O
default	O
Raiden	B-Application
DX	I-Application
soundtrack	O
to	O
implement	O
music	O
from	O
Viper	B-Application
Phase	I-Application
1	I-Application
.	O
</s>
<s>
Viper	B-Application
Phase	I-Application
1	I-Application
runs	O
on	O
the	O
Seibu	B-Application
SPI	I-Application
System	I-Application
hardware	O
.	O
</s>
<s>
The	O
later	O
Raiden	B-Application
Fighters	I-Application
series	O
uses	O
the	O
same	O
hardware	O
.	O
</s>
<s>
In	O
Japan	O
,	O
Game	O
Machine	O
listed	O
Viper	B-Application
Phase	I-Application
1	I-Application
on	O
their	O
July	O
1	O
,	O
1995	O
issue	O
as	O
being	O
the	O
ninth	O
most-successful	O
arcade	O
game	O
of	O
the	O
month	O
.	O
</s>
<s>
In	O
North	O
America	O
,	O
RePlay	O
reported	O
Viper	B-Application
Phase	I-Application
1	I-Application
was	O
the	O
sixth	O
most-popular	O
arcade	O
game	O
at	O
the	O
time	O
.	O
</s>
