<s>
TI	B-Application
Invaders	I-Application
is	O
a	O
fixed	O
shooter	O
video	O
game	O
published	O
by	O
Texas	O
Instruments	O
in	O
1981	O
for	O
the	O
TI-99/4A	B-Device
home	O
computer	O
.	O
</s>
<s>
The	O
game	O
is	O
a	O
Space	B-Application
Invaders	I-Application
clone	O
where	O
the	O
goal	O
is	O
to	O
shoot	O
all	O
of	O
the	O
aliens	O
before	O
they	O
reach	O
the	O
bottom	O
of	O
the	O
screen	O
.	O
</s>
<s>
TI	B-Application
Invaders	I-Application
is	O
part	O
of	O
the	O
TI	O
Arcade	O
Game	O
Series	O
which	O
includes	O
Tombstone	B-Application
City	I-Application
:	I-Application
21st	I-Application
Century	I-Application
and	O
Car	B-Application
Wars	I-Application
.	O
</s>
<s>
TI	B-Application
Invaders	I-Application
is	O
a	O
single-player	O
fixed	O
shooter	O
.	O
</s>
<s>
As	O
in	O
Space	B-Application
Invaders	I-Application
,	O
which	O
TI	B-Application
Invaders	I-Application
is	O
a	O
video	O
game	O
clone	O
of	O
,	O
a	O
UFO	B-Application
will	O
appear	O
once	O
or	O
twice	O
a	O
round	O
and	O
travel	O
from	O
one	O
end	O
of	O
the	O
screen	O
to	O
the	O
other	O
.	O
</s>
<s>
The	O
player	O
has	O
the	O
opportunity	O
to	O
hit	O
it	O
to	O
score	O
bonus	O
points	O
,	O
the	O
amount	O
depending	O
on	O
where	O
the	O
UFO	B-Application
is	O
hit	O
.	O
</s>
<s>
After	O
each	O
level	O
is	O
cleared	O
,	O
there	O
is	O
a	O
bonus	O
round	O
consisting	O
only	O
of	O
one	O
UFO	B-Application
.	O
</s>
<s>
The	O
UFO	B-Application
travels	O
slowly	O
from	O
one	O
end	O
of	O
the	O
screen	O
to	O
the	O
other	O
until	O
it	O
is	O
hit	O
for	O
the	O
first	O
time	O
,	O
then	O
it	O
returns	O
other	O
way	O
at	O
twice	O
its	O
original	O
speed	O
.	O
</s>
<s>
The	O
player	O
must	O
track	O
it	O
to	O
the	O
other	O
side	O
of	O
the	O
screen	O
and	O
shoot	O
it	O
again	O
,	O
making	O
the	O
UFO	B-Application
return	O
in	O
the	O
other	O
direction	O
again	O
.	O
</s>
<s>
The	O
UFO	B-Application
's	O
score	O
value	O
increases	O
gradually	O
with	O
each	O
hit	O
,	O
and	O
the	O
UFO	B-Application
gets	O
smaller	O
and	O
smaller	O
.	O
</s>
<s>
This	O
continues	O
until	O
either	O
the	O
player	O
eliminates	O
the	O
UFO	B-Application
completely	O
,	O
or	O
it	O
escapes	O
off	O
the	O
screen	O
.	O
</s>
<s>
Also	O
,	O
as	O
in	O
Space	B-Application
Invaders	I-Application
,	O
if	O
any	O
number	O
of	O
invaders	O
hits	O
the	O
bottom	O
row	O
,	O
the	O
closest	O
one	O
to	O
the	O
missile	O
will	O
shoot	O
it	O
from	O
the	O
side	O
and	O
the	O
game	O
is	O
over	O
regardless	O
of	O
the	O
number	O
of	O
reserve	O
missiles	O
left	O
.	O
</s>
<s>
In	O
1982	O
,	O
TI	B-Application
Invaders	I-Application
was	O
listed	O
as	O
one	O
of	O
the	O
top-selling	O
computer	O
games	O
for	O
the	O
TI-99/4A	B-Device
along	O
with	O
Hunt	B-Application
the	I-Application
Wumpus	I-Application
.	O
</s>
