<s>
Commander	B-Application
Keen	I-Application
is	O
a	O
side-scrolling	O
platform	O
video	O
game	O
developed	O
by	O
David	O
A	O
.	O
Palmer	O
Productions	O
and	O
published	O
by	O
Activision	O
in	O
June	O
2001	O
for	O
the	O
Game	B-Device
Boy	I-Device
Color	I-Device
.	O
</s>
<s>
Part	O
of	O
the	O
Commander	B-Application
Keen	I-Application
series	O
,	O
it	O
was	O
released	O
ten	O
years	O
after	O
the	O
first	O
seven	O
episodes	O
in	O
1990	O
–	O
91	O
.	O
</s>
<s>
The	O
game	O
follows	O
the	O
titular	O
Commander	B-Application
Keen	I-Application
,	O
an	O
eight-year-old	O
child	O
genius	O
,	O
as	O
he	O
journeys	O
through	O
three	O
alien	O
worlds	O
to	O
collect	O
three	O
plasma	O
crystals	O
to	O
prevent	O
the	O
weapon	O
they	O
power	O
,	O
built	O
by	O
several	O
enemies	O
from	O
previous	O
games	O
,	O
from	O
destroying	O
the	O
universe	O
.	O
</s>
<s>
The	O
original	O
games	O
of	O
the	O
Commander	B-Application
Keen	I-Application
series	O
were	O
developed	O
by	O
id	O
Software	O
,	O
but	O
after	O
the	O
success	O
of	O
their	O
3D	O
first-person	O
shooters	O
such	O
as	O
Wolfenstein	B-Application
3D	I-Application
(	O
1992	O
)	O
and	O
Doom	B-Application
(	O
1993	O
)	O
,	O
they	O
canceled	O
the	O
planned	O
future	O
episodes	O
in	O
the	O
series	O
.	O
</s>
<s>
In	O
1999	O
,	O
founder	O
John	O
Carmack	O
remarked	O
that	O
he	O
was	O
considering	O
making	O
a	O
Game	B-Device
Boy	I-Device
Color	I-Device
game	O
for	O
the	O
series	O
,	O
and	O
sometime	O
afterwards	O
id	O
approached	O
Activision	O
with	O
the	O
idea	O
.	O
</s>
<s>
Activision	O
recommended	O
David	O
A	O
.	O
Palmer	O
Productions	O
to	O
develop	O
the	O
game	O
,	O
as	O
they	O
had	O
been	O
proposing	O
to	O
make	O
Game	B-Device
Boy	I-Device
Color	I-Device
versions	O
of	O
id	O
's	O
other	O
games	O
,	O
and	O
Palmer	O
proceeded	O
to	O
make	O
the	O
game	O
with	O
oversight	O
from	O
id	O
.	O
</s>
<s>
It	O
received	O
mixed	O
reviews	O
from	O
critics	O
,	O
who	O
gave	O
varied	O
opinions	O
on	O
the	O
quality	O
of	O
the	O
game	O
's	O
graphics	O
and	O
the	O
suitability	O
of	O
the	O
ten-year-old	O
computer-based	O
gameplay	O
on	O
a	O
modern	O
handheld	B-Application
game	I-Application
console	I-Application
,	O
and	O
generally	O
found	O
the	O
game	O
best	O
suited	O
for	O
fans	O
of	O
the	O
original	O
series	O
or	O
younger	O
players	O
.	O
</s>
<s>
Commander	B-Application
Keen	I-Application
is	O
a	O
side-scrolling	O
platform	O
video	O
game	O
:	O
the	O
majority	O
of	O
the	O
game	O
features	O
the	O
player-controlled	O
Commander	B-Application
Keen	I-Application
viewed	O
from	O
the	O
side	O
while	O
moving	O
on	O
a	O
two-dimensional	O
plane	O
.	O
</s>
<s>
The	O
levels	O
are	O
composed	O
of	O
platforms	O
on	O
which	O
Keen	O
can	O
stand	O
,	O
viewed	O
from	O
the	O
side	O
as	O
in	O
the	O
original	O
Commander	B-Application
Keen	I-Application
in	I-Application
Invasion	I-Application
of	I-Application
the	I-Application
Vorticons	I-Application
trilogy	O
,	O
and	O
some	O
platforms	O
allow	O
Keen	O
to	O
jump	O
up	O
through	O
them	O
from	O
below	O
.	O
</s>
<s>
While	O
the	O
raygun	O
in	O
Vorticons	B-Application
killed	O
enemies	O
,	O
and	O
the	O
stun	O
gun	O
in	O
Goodbye	B-Application
,	I-Application
Galaxy	I-Application
and	O
Aliens	B-Application
Ate	I-Application
My	I-Application
Babysitter	I-Application
permanently	O
stunned	O
them	O
,	O
Keen	O
's	O
Neural	O
Ray	O
Blaster	O
in	O
this	O
game	O
only	O
temporarily	O
stuns	O
enemies	O
,	O
who	O
must	O
then	O
be	O
jumped	O
on	O
with	O
the	O
pogo	O
stick	O
to	O
be	O
killed	O
or	O
destroyed	O
.	O
</s>
<s>
Donning	O
his	O
helmet	O
as	O
Commander	B-Application
Keen	I-Application
,	O
Billy	O
rushes	O
off	O
to	O
discover	O
what	O
is	O
affecting	O
the	O
Earth	O
.	O
</s>
<s>
He	O
flies	O
to	O
the	O
source	O
,	O
only	O
to	O
discover	O
that	O
the	O
Shikadi	O
from	O
Goodbye	B-Application
,	I-Application
Galaxy	I-Application
,	O
the	O
Bloogs	O
from	O
Aliens	B-Application
Ate	I-Application
My	I-Application
Babysitter	I-Application
,	O
and	O
his	O
"	O
old	O
enemies	O
"	O
the	O
Droidicus	O
—	O
not	O
present	O
in	O
a	O
previous	O
game	O
—	O
have	O
joined	O
forces	O
and	O
are	O
working	O
with	O
his	O
arch-rival	O
Mortimer	O
McMire	O
.	O
</s>
<s>
The	O
Commander	B-Application
Keen	I-Application
series	O
originated	O
in	O
1990	O
when	O
John	O
Carmack	O
,	O
then	O
a	O
game	O
programmer	O
at	O
Softdisk	O
,	O
devised	O
a	O
method	O
called	O
adaptive	O
tile	O
refresh	O
to	O
produce	O
smoothly	O
scrolling	O
graphics	O
for	O
a	O
2D	O
platform	O
video	O
game	O
engine	O
on	O
IBM	O
PC	O
compatible	O
general-purpose	O
computers	O
.	O
</s>
<s>
Using	O
this	O
engine	O
,	O
they	O
created	O
a	O
PC	O
demo	O
clone	O
of	O
Super	B-Application
Mario	I-Application
Bros	I-Application
.	I-Application
3	I-Application
,	O
but	O
were	O
unable	O
to	O
interest	O
Nintendo	O
in	O
it	O
.	O
</s>
<s>
Carmack	O
and	O
a	O
group	O
of	O
his	O
coworkers	O
from	O
Softdisk	O
—	O
including	O
programmer	O
John	O
Romero	O
,	O
designer	O
Tom	O
Hall	O
,	O
and	O
artist	O
Adrian	O
Carmack	O
—	O
used	O
their	O
tile	O
scrolling	O
technique	O
to	O
make	O
an	O
original	O
trilogy	O
of	O
shareware	B-License
episodes	O
for	O
publisher	O
Apogee	O
Software	O
.	O
</s>
<s>
The	O
game	O
,	O
Commander	B-Application
Keen	I-Application
in	I-Application
Invasion	I-Application
of	I-Application
the	I-Application
Vorticons	I-Application
,	O
was	O
a	O
large	O
success	O
for	O
the	O
market	O
,	O
and	O
led	O
the	O
group	O
to	O
quit	O
their	O
jobs	O
and	O
found	O
id	O
Software	O
.	O
</s>
<s>
The	O
game	O
was	O
followed	O
by	O
four	O
more	O
episodes	O
during	O
1991	O
:	O
Keen	B-Application
Dreams	I-Application
,	O
a	O
pair	O
titled	O
Goodbye	B-Application
,	I-Application
Galaxy	I-Application
,	O
and	O
Aliens	B-Application
Ate	I-Application
My	I-Application
Babysitter	I-Application
.	O
</s>
<s>
Further	O
plans	O
were	O
made	O
for	O
another	O
trilogy	O
to	O
be	O
produced	O
in	O
1992	O
under	O
the	O
name	O
The	O
Universe	O
is	O
Toast	O
,	O
but	O
before	O
any	O
work	O
began	O
it	O
was	O
canceled	O
due	O
to	O
the	O
success	O
of	O
id	O
's	O
Wolfenstein	B-Application
3D	I-Application
and	O
development	O
focus	O
on	O
Doom	B-Application
.	O
</s>
<s>
In	O
October	O
1999	O
during	O
an	O
online	O
question	O
and	O
answer	O
session	O
,	O
John	O
Carmack	O
,	O
while	O
discussing	O
that	O
the	O
original	O
founders	O
of	O
id	O
Software	O
were	O
unlikely	O
to	O
ever	O
work	O
together	O
on	O
a	O
game	O
again	O
,	O
mentioned	O
that	O
he	O
was	O
considering	O
the	O
idea	O
of	O
making	O
a	O
Commander	B-Application
Keen	I-Application
game	O
for	O
the	O
Game	B-Device
Boy	I-Device
Color	I-Device
handheld	B-Application
game	I-Application
console	I-Application
.	O
</s>
<s>
IGN	O
,	O
when	O
reporting	O
the	O
statement	O
,	O
mentioned	O
that	O
the	O
idea	O
was	O
not	O
unfeasible	O
,	O
especially	O
given	O
that	O
another	O
1991	O
side-scroller	O
,	O
Apogee	O
's	O
Duke	B-Application
Nukem	I-Application
,	O
had	O
just	O
been	O
ported	O
to	O
the	O
same	O
platform	O
.	O
</s>
<s>
Activision	O
formally	O
announced	O
at	O
the	O
start	O
of	O
May	O
that	O
a	O
new	O
Commander	B-Application
Keen	I-Application
game	O
had	O
been	O
developed	O
by	O
David	O
A	O
.	O
Palmer	O
Productions	O
,	O
and	O
would	O
be	O
released	O
at	O
the	O
end	O
of	O
the	O
month	O
.	O
</s>
<s>
Palmer	O
greatly	O
admired	O
id	O
's	O
games	O
,	O
and	O
had	O
been	O
attempting	O
to	O
get	O
an	O
agreement	O
with	O
id	O
and	O
Activision	O
for	O
several	O
years	O
for	O
his	O
studio	O
to	O
make	O
a	O
Game	B-Device
Boy	I-Device
Color	I-Device
version	O
of	O
several	O
of	O
their	O
games	O
,	O
such	O
as	O
the	O
1993	O
Doom	B-Application
or	O
1996	O
Quake	B-Application
.	O
</s>
<s>
This	O
was	O
further	O
elaborated	O
on	O
in	O
the	O
David	O
A	O
.	O
Palmer	O
interview	O
,	O
who	O
clarified	O
that	O
the	O
game	O
incorporated	O
elements	O
from	O
multiple	O
games	O
in	O
the	O
series	O
,	O
with	O
care	O
taken	O
to	O
keep	O
them	O
as	O
similar	O
as	O
possible	O
to	O
the	O
original	O
games	O
;	O
he	O
noted	O
that	O
it	O
did	O
not	O
include	O
elements	O
from	O
some	O
games	O
,	O
like	O
Keen	B-Application
Dreams	I-Application
,	O
where	O
id	O
did	O
not	O
hold	O
the	O
rights	O
.	O
</s>
<s>
Commander	B-Application
Keen	I-Application
received	O
mixed	O
reviews	O
from	O
critics	O
.	O
</s>
<s>
GameSpot	O
's	O
Provo	O
termed	O
the	O
difficult	O
gameplay	O
an	O
"	O
acquired	O
taste	O
"	O
,	O
and	O
one	O
which	O
was	O
better	O
suited	O
to	O
a	O
system	O
where	O
players	O
could	O
save	O
anywhere	O
,	O
while	O
AllGame	O
's	O
White	O
criticized	O
the	O
size	O
of	O
the	O
levels	O
,	O
which	O
he	O
felt	O
were	O
ill-suited	O
to	O
the	O
small	O
screen	O
of	O
the	O
Game	B-Device
Boy	I-Device
Color	I-Device
and	O
which	O
led	O
to	O
tedious	O
hunting	O
for	O
where	O
to	O
go	O
next	O
.	O
</s>
