<s>
Head	B-Application
On	I-Application
is	O
an	O
arcade	B-Application
video	I-Application
game	I-Application
developed	O
by	O
Sega/Gremlin	O
and	O
released	O
by	O
Sega	O
in	O
1979	O
.	O
</s>
<s>
It	O
's	O
the	O
first	O
maze	B-Application
game	I-Application
where	O
the	O
goal	O
is	O
to	O
run	O
over	O
dots	O
.	O
</s>
<s>
Sega	O
released	O
a	O
sequel	O
,	O
Head	B-Application
On	I-Application
Part	O
II	O
,	O
later	O
the	O
same	O
year	O
.	O
</s>
<s>
The	O
original	O
inspired	O
a	O
number	O
of	O
clones	O
,	O
as	O
well	O
as	O
Namco	O
's	O
Rally-X	B-Application
(	O
1980	O
)	O
.	O
</s>
<s>
Two	O
cars	O
continuously	O
drive	O
forward	O
through	O
rectangular	O
channels	O
in	O
a	O
simple	O
maze	B-Application
.	O
</s>
<s>
The	O
player	O
goal	O
is	O
to	O
collect	O
all	O
dots	O
in	O
the	O
maze	B-Application
while	O
avoiding	O
collisions	O
with	O
the	O
computer-controlled	O
car	O
that	O
is	O
travelling	O
in	O
the	O
opposite	O
direction	O
.	O
</s>
<s>
After	O
the	O
acquisition	O
,	O
a	O
veteran	O
Sega	O
engineer	O
in	O
Japan	O
had	O
a	O
look	O
at	O
a	O
prototype	O
of	O
Head	B-Application
On	I-Application
and	O
was	O
interested	O
.	O
</s>
<s>
At	O
the	O
time	O
,	O
Taito	O
's	O
Space	B-Application
Invaders	I-Application
had	O
introduced	O
the	O
concept	O
of	O
"	O
going	O
round	O
after	O
round	O
"	O
so	O
the	O
Sega	O
engineer	O
suggested	O
to	O
Hauck	O
that	O
he	O
should	O
get	O
rid	O
of	O
the	O
timer	O
and	O
replace	O
it	O
with	O
a	O
Space	B-Application
Invaders	I-Application
like	O
round-after-round	O
concept	O
,	O
which	O
Hauck	O
subsequently	O
implemented	O
and	O
later	O
said	O
was	O
"	O
a	O
key	O
to	O
making	O
the	O
game	O
big.	O
"	O
</s>
<s>
After	O
the	O
game	O
was	O
complete	O
,	O
Sega	O
marketed	O
the	O
game	O
in	O
Japan	O
,	O
while	O
Gremlin	O
in	O
turn	O
marketed	O
Sega	O
games	O
such	O
as	O
Monaco	B-Application
GP	I-Application
in	O
North	O
America	O
.	O
</s>
<s>
Head	B-Application
On	I-Application
was	O
a	O
commercial	O
success	O
in	O
arcades	O
.	O
</s>
<s>
It	O
was	O
Japan	O
's	O
fourth	O
highest-grossing	O
arcade	B-Application
game	I-Application
of	I-Application
1979	I-Application
,	O
below	O
Space	B-Application
Invaders	I-Application
,	O
Galaxian	B-Application
and	O
Sega	O
's	O
Monaco	B-Application
GP	I-Application
.	O
</s>
<s>
Head	B-Application
On	I-Application
was	O
also	O
the	O
fourth	O
highest-earning	O
arcade	B-Application
video	I-Application
game	I-Application
of	O
1979	O
in	O
the	O
United	O
States	O
,	O
below	O
Space	B-Application
Invaders	I-Application
,	O
Football	B-Application
and	O
Sprint	B-Application
2	I-Application
.	O
</s>
<s>
Ports	O
of	O
Head	B-Application
On	I-Application
for	O
the	O
Commodore	O
64	O
and	O
VIC-20	B-Device
were	O
released	O
in	O
1982	O
.	O
</s>
<s>
In	O
Japan	O
,	O
the	O
game	O
was	O
released	O
for	O
the	O
PC-8801	B-Device
and	O
Sharp	B-Operating_System
MZ	I-Operating_System
computers	O
.	O
</s>
<s>
Head	B-Application
On	I-Application
later	O
appeared	O
in	O
the	O
Sega	B-Device
Saturn	I-Device
collection	O
Sega	O
Memorial	O
Selection	O
Vol.1	O
and	O
in	O
the	O
PlayStation	B-Device
2	I-Device
collection	O
Sega	O
Ages	O
Vol	O
.	O
</s>
<s>
A	O
similar	O
sequel	O
was	O
released	O
the	O
same	O
year	O
as	O
the	O
original	O
:	O
Head	B-Application
On	I-Application
Part	O
II	O
,	O
also	O
known	O
as	O
Head	B-Application
On	I-Application
2	O
.	O
</s>
<s>
Namco	O
's	O
Rally-X	B-Application
was	O
produced	O
as	O
a	O
successor	O
to	O
Head	B-Application
On	I-Application
.	O
</s>
<s>
A	O
spiritual	O
successor	O
,	O
Pacar	O
,	O
was	O
released	O
for	O
the	O
SG-1000	B-Operating_System
.	O
</s>
<s>
It	O
adds	O
a	O
faux	O
3D	O
environment	O
,	O
multiple	O
enemy	O
cars	O
that	O
chase	O
the	O
player	O
in	O
varying	O
ways	O
,	O
tunnels	O
that	O
exit	O
the	O
maze	B-Application
,	O
and	O
power	O
pellets	O
that	O
are	O
produced	O
by	O
the	O
player	O
to	O
eliminate	O
enemy	O
cars	O
.	O
</s>
<s>
These	O
additions	O
make	O
it	O
more	O
like	O
a	O
Pac-Man	B-Application
clone	O
.	O
</s>
<s>
A	O
mobile	O
phone	O
version	O
of	O
Head	B-Application
On	I-Application
was	O
released	O
exclusively	O
in	O
Japan	O
through	O
the	O
Sonic	O
Cafe	O
,	O
Puyo	O
Puyo	O
Sega	O
,	O
and	O
Sega	O
Ages	O
portal	O
during	O
the	O
2000s	O
.	O
</s>
<s>
Exidy	O
's	O
Crash	O
was	O
released	O
in	O
arcades	O
the	O
same	O
year	O
as	O
Head	B-Application
On	I-Application
.	O
</s>
<s>
It	O
was	O
the	O
seventh	O
highest-grossing	O
arcade	B-Application
game	I-Application
of	I-Application
1979	I-Application
in	O
the	O
United	O
States	O
.	O
</s>
<s>
Konami	O
's	O
Fast	B-Application
Lane	I-Application
arcade	B-Application
game	O
,	O
released	O
in	O
1987	O
,	O
is	O
a	O
Head	B-Application
On	I-Application
clone	O
with	O
improved	O
graphics	O
and	O
some	O
additional	O
features	O
.	O
</s>
<s>
Head	B-Application
On	I-Application
proved	O
a	O
popular	O
concept	O
to	O
clone	O
for	O
home	O
systems	O
.	O
</s>
<s>
Clones	O
include	O
Car	B-Application
Wars	I-Application
for	O
the	O
TI-99/4A	B-Device
,	O
Killer	O
Car	O
for	O
Spectravideo	O
,	O
Car	O
Chase	O
for	O
the	O
ZX	B-Operating_System
Spectrum	I-Operating_System
,	O
Dodge	B-Application
'	I-Application
Em	I-Application
for	O
the	O
Atari	B-General_Concept
2600	I-General_Concept
,	O
Dodge	O
Racer	O
for	O
the	O
Atari	B-Device
8-bit	I-Device
family	I-Device
,	O
and	O
Tunnels	O
of	O
Fahad	O
for	O
the	O
TRS-80	B-Device
.	O
</s>
