<s>
Etrian	B-Application
Mystery	I-Application
Dungeon	I-Application
is	O
a	O
role-playing	O
video	O
game	O
for	O
the	O
Nintendo	B-Operating_System
3DS	I-Operating_System
.	O
</s>
<s>
The	O
game	O
is	O
a	O
crossover	O
between	O
Atlus	O
 '	O
Etrian	B-Application
Odyssey	I-Application
series	O
and	O
Spike	O
Chunsoft	O
's	O
Mystery	O
Dungeon	O
series	O
.	O
</s>
<s>
A	O
sequel	O
,	O
Etrian	B-Application
Mystery	I-Application
Dungeon	I-Application
2	O
,	O
was	O
released	O
in	O
Japan	O
on	O
August	O
31	O
,	O
2017	O
.	O
</s>
<s>
The	O
game	O
features	O
the	O
character	O
customization	O
and	O
character	O
class	O
system	O
from	O
the	O
Etrian	B-Application
Odyssey	I-Application
series	O
,	O
and	O
the	O
dungeon	O
crawling	O
from	O
the	O
Mystery	O
Dungeon	O
series	O
;	O
the	O
player	O
's	O
party	O
,	O
which	O
is	O
made	O
up	O
of	O
custom-made	O
characters	O
,	O
ventures	O
into	O
randomly	O
generated	O
multi-floor	O
dungeons	O
,	O
with	O
the	O
objective	O
to	O
reach	O
the	O
end	O
of	O
each	O
dungeon	O
.	O
</s>
<s>
If	O
the	O
player	O
gets	O
a	O
game	B-Application
over	I-Application
,	O
their	O
party	O
is	O
sent	O
back	O
to	O
the	O
town	O
outside	O
the	O
dungeons	O
;	O
additionally	O
,	O
the	O
player	O
loses	O
all	O
their	O
in-game	O
money	O
and	O
items	O
.	O
</s>
<s>
If	O
they	O
succeed	O
,	O
the	O
player	O
will	O
get	O
a	O
game	B-Application
over	I-Application
,	O
and	O
certain	O
facilities	O
in	O
the	O
town	O
will	O
be	O
destroyed	O
and	O
rendered	O
unusable	O
by	O
the	O
player	O
for	O
some	O
time	O
;	O
it	O
is	O
up	O
to	O
the	O
player	O
to	O
protect	O
the	O
town	O
by	O
fighting	O
these	O
enemies	O
.	O
</s>
<s>
The	O
game	O
was	O
developed	O
by	O
Spike	O
Chunsoft	O
and	O
Atlus	O
,	O
the	O
developers	O
of	O
the	O
Mystery	O
Dungeon	O
and	O
Etrian	B-Application
Odyssey	I-Application
series	O
,	O
respectively	O
,	O
with	O
most	O
of	O
the	O
actual	O
development	O
done	O
at	O
Spike	O
Chunsoft	O
,	O
while	O
Atlus	O
acted	O
as	O
supervisors	O
.	O
</s>
<s>
Background	O
designs	O
were	O
handled	O
by	O
Nizo	O
Yamamoto	O
,	O
while	O
character	O
design	O
was	O
split	O
between	O
Kaoru	O
Hasegawa	O
who	O
designed	O
the	O
character	O
classes	O
,	O
and	O
Shin	O
Nagasawa	O
who	O
designed	O
the	O
enemies	O
;	O
additionally	O
,	O
some	O
character	O
designs	O
from	O
previous	O
Etrian	B-Application
Odyssey	I-Application
games	O
,	O
done	O
by	O
Yuji	O
Himukai	O
,	O
were	O
brought	O
back	O
for	O
Etrian	B-Application
Mystery	I-Application
Dungeon	I-Application
.	O
</s>
<s>
During	O
development	O
,	O
both	O
the	O
companies	O
would	O
continuously	O
share	O
their	O
most	O
recent	O
data	O
on	O
a	O
shared	O
server	B-Application
,	O
and	O
discuss	O
details	O
of	O
the	O
game	O
direction	O
using	O
an	O
instant	O
messaging	O
program	O
;	O
additionally	O
,	O
they	O
would	O
hold	O
weekly	O
meetings	O
during	O
which	O
they	O
made	O
various	O
arrangements	O
for	O
the	O
game	O
,	O
and	O
every	O
month	O
during	O
development	O
,	O
Spike	O
Chunsoft	O
would	O
send	O
their	O
latest	O
playable	O
build	O
to	O
Atlus	O
,	O
who	O
would	O
check	O
the	O
direction	O
the	O
game	O
was	O
going	O
in	O
.	O
</s>
<s>
Character	O
classes	O
that	O
were	O
brought	O
in	O
from	O
the	O
two	O
series	O
had	O
to	O
be	O
carefully	O
considered	O
in	O
order	O
to	O
maintain	O
game	O
balance	O
and	O
to	O
avoid	O
overlap	O
with	O
other	O
classes	O
;	O
for	O
instance	O
,	O
the	O
Gunner	O
class	O
was	O
chosen	O
to	O
be	O
the	O
"	O
ranged	O
attacker	O
"	O
class	O
of	O
the	O
game	O
rather	O
than	O
the	O
similar	O
Survivalist	O
class	O
—	O
a	O
class	O
introduced	O
in	O
the	O
first	O
Etrian	B-Application
Odyssey	I-Application
game	O
—	O
as	O
the	O
Survivalists	O
in	O
addition	O
to	O
their	O
ranged	O
attacks	O
have	O
several	O
skills	O
that	O
assist	O
with	O
dungeon	O
exploration	O
,	O
and	O
thus	O
would	O
overlap	O
with	O
the	O
abilities	O
of	O
the	O
Wanderer	O
class	O
-	O
a	O
class	O
based	O
on	O
the	O
player	O
character	O
in	O
the	O
Mystery	O
Dungeon	O
:	O
Shiren	O
the	O
Wanderer	O
series	O
.	O
</s>
<s>
Another	O
class	O
that	O
was	O
considered	O
for	O
the	O
"	O
ranged	O
attacker	O
"	O
role	O
was	O
the	O
Arbalist	O
—	O
a	O
class	O
from	O
Etrian	B-Application
Odyssey	I-Application
III	I-Application
:	I-Application
The	I-Application
Drowned	I-Application
City	I-Application
—	O
but	O
due	O
to	O
its	O
high	O
damage	O
output	O
it	O
would	O
have	O
been	O
very	O
difficult	O
to	O
balance	O
the	O
game	O
had	O
it	O
been	O
included	O
.	O
</s>
<s>
Another	O
factor	O
in	O
choosing	O
the	O
Gunner	O
was	O
that	O
it	O
already	O
was	O
a	O
popular	O
class	O
in	O
the	O
Etrian	B-Application
Odyssey	I-Application
series	O
,	O
and	O
had	O
been	O
made	O
into	O
figurines	O
in	O
Japan	O
.	O
</s>
<s>
In	O
addition	O
to	O
new	O
compositions	O
,	O
the	O
soundtrack	O
also	O
includes	O
arranged	O
music	O
from	O
previous	O
Etrian	B-Application
Odyssey	I-Application
games	O
.	O
</s>
<s>
The	O
first	O
print	O
of	O
the	O
Japanese	O
release	O
came	O
bundled	O
with	O
a	O
copy	O
of	O
an	O
Etrian	B-Application
Mystery	I-Application
Dungeon	I-Application
themed	O
issue	O
of	O
Marukatsu	O
Super	O
Famicom	O
—	O
a	O
Japanese	O
video	O
game	O
magazine	O
that	O
had	O
not	O
been	O
in	O
print	O
since	O
its	O
final	O
issue	O
23	O
years	O
previously	O
—	O
titled	O
Marukatsu	O
Super	O
Famicom	O
2015	O
Revival	O
Edition	O
,	O
including	O
52	O
pages	O
of	O
information	O
and	O
artwork	O
related	O
to	O
the	O
game	O
,	O
as	O
well	O
as	O
a	O
soundtrack	O
CD	O
with	O
six	O
songs	O
from	O
the	O
game	O
.	O
</s>
<s>
Players	O
of	O
the	O
North	O
American	O
version	O
were	O
able	O
to	O
get	O
five	O
pieces	O
of	O
downloadable	B-Protocol
content	I-Protocol
for	O
free	O
during	O
the	O
first	O
month	O
following	O
the	O
game	O
's	O
release	O
.	O
</s>
<s>
Etrian	B-Application
Mystery	I-Application
Dungeon	I-Application
was	O
the	O
second	O
highest	O
selling	O
video	O
game	O
in	O
Japan	O
during	O
its	O
opening	O
week	O
,	O
with	O
65,226	O
copies	O
sold	O
and	O
91.96	O
%	O
of	O
the	O
initial	O
shipment	O
sold	O
out	O
.	O
</s>
