<s>
Critical	B-Application
Mass	I-Application
(	O
known	O
as	O
Power	B-Application
!	I-Application
</s>
<s>
in	O
North	O
America	O
)	O
is	O
a	O
video	O
game	O
developed	O
by	O
Simon	O
Francis	O
and	O
published	O
in	O
1985	O
by	O
Durell	O
Software	O
for	O
the	O
Amstrad	B-Device
CPC	I-Device
,	O
Commodore	O
64	O
,	O
and	O
ZX	B-Operating_System
Spectrum	I-Operating_System
.	O
</s>
<s>
The	O
station	O
has	O
been	O
taken	O
over	O
by	O
hostile	O
aliens	O
who	O
are	O
threatening	O
to	O
overload	O
the	O
power	O
system	O
which	O
will	O
turn	O
the	O
reactor	O
into	O
a	O
massive	O
black	B-Application
hole	I-Application
and	O
destroy	O
not	O
only	O
the	O
planetary	O
system	O
,	O
but	O
several	O
nearby	O
stars	O
as	O
well	O
.	O
</s>
<s>
The	O
object	O
of	O
the	O
game	O
is	O
to	O
make	O
it	O
to	O
the	O
heavily	O
defended	O
power	O
station	O
and	O
disable	O
it	O
before	O
the	O
reactor	O
reaches	O
critical	B-Application
mass	I-Application
and	O
implodes	O
.	O
</s>
