<s>
Zoo	B-Device
Keeper	I-Device
is	O
a	O
tile-matching	B-Application
video	I-Application
game	I-Application
developed	O
for	O
the	O
Web	O
by	O
Robot	O
Communications	O
and	O
later	O
ported	O
to	O
the	O
Nintendo	B-Device
DS	I-Device
by	O
Japanese	O
video	O
game	O
publisher	O
Success	O
.	O
</s>
<s>
Zoo	B-Device
Keeper	I-Device
was	O
released	O
for	O
arcades	O
in	O
2004	O
.	O
</s>
<s>
The	O
game	O
was	O
then	O
brought	O
to	O
American	O
and	O
European	O
shores	O
by	O
Ignition	O
Entertainment	O
,	O
and	O
has	O
since	O
been	O
released	O
for	O
iOS	B-Operating_System
and	O
Android	B-Application
devices	O
under	O
the	O
title	O
Zookeeper	O
DX	O
Touch	O
Edition	O
by	O
Kiteretsu	O
.	O
</s>
<s>
In	O
Japan	O
,	O
before	O
the	O
release	O
for	O
Nintendo	B-Device
DS	I-Device
,	O
Success	O
released	O
this	O
game	O
for	O
Game	B-Device
Boy	I-Device
Advance	I-Device
and	O
PlayStation	B-Device
2	I-Device
with	O
alternative	O
name	O
Zooo	B-Device
.	O
</s>
<s>
The	O
PlayStation	B-Device
2	I-Device
version	O
of	O
this	O
game	O
was	O
later	O
released	O
in	O
Europe	O
by	O
505	O
Game	O
Street	O
as	O
Zoo	O
Puzzle	O
.	O
</s>
<s>
The	O
objective	O
of	O
Zoo	B-Device
Keeper	I-Device
is	O
to	O
remove	O
the	O
animal	O
tiles	O
that	O
fill	O
up	O
the	O
screen	O
by	O
aligning	O
three	O
or	O
more	O
in	O
a	O
row	O
or	O
column	O
.	O
</s>
<s>
One	O
very	O
important	O
aspect	O
that	O
sets	O
Zoo	B-Device
Keeper	I-Device
apart	O
from	O
Bejeweled	O
and	O
its	O
many	O
clones	O
is	O
the	O
ability	O
to	O
switch	O
tiles	O
while	O
another	O
move	O
is	O
still	O
'	O
in	O
progress	O
 '	O
.	O
</s>
<s>
A	O
key	O
challenge	O
when	O
playing	O
Zoo	B-Device
Keeper	I-Device
is	O
the	O
inability	O
to	O
find	O
a	O
valid	O
move	O
,	O
which	O
players	O
know	O
must	O
exist	O
(	O
otherwise	O
the	O
screen	O
would	O
be	O
reset	O
)	O
.	O
</s>
<s>
On	O
the	O
DS	B-Device
version	O
of	O
the	O
game	O
,	O
as	O
shown	O
in	O
the	O
screenshot	O
,	O
the	O
upper	O
screen	O
shows	O
a	O
favourite	O
animal	O
,	O
for	O
which	O
captures	O
generate	O
increased	O
points	O
.	O
</s>
<s>
It	O
utilises	O
touch	O
screen	O
operation	O
and	O
the	O
opportunity	O
to	O
battle	O
another	O
DS	B-Device
owner	O
.	O
</s>
<s>
Zoo	B-Device
Keeper	I-Device
mode	O
sets	O
a	O
quota	O
of	O
animal	O
tiles	O
to	O
remove	O
in	O
order	O
to	O
advance	O
a	O
level	O
.	O
</s>
