<s>
is	O
a	O
2010	O
platform	O
game	O
developed	O
by	O
Dimps	O
,	O
with	O
assistance	O
from	O
Sonic	B-Application
Team	O
,	O
and	O
published	O
by	O
Sega	O
.	O
</s>
<s>
It	O
is	O
a	O
sequel	O
to	O
Sonic	B-Application
&	I-Application
Knuckles	I-Application
(	O
1994	O
)	O
,	O
following	O
Sonic	B-Application
as	O
he	O
sets	O
out	O
to	O
stop	O
a	O
returning	O
Doctor	O
Eggman	O
.	O
</s>
<s>
Like	O
the	O
Sonic	B-Application
the	I-Application
Hedgehog	I-Application
games	O
released	O
for	O
the	O
Sega	B-Operating_System
Genesis	I-Operating_System
,	O
Episode	O
I	O
features	O
side-scrolling	O
gameplay	O
,	O
with	O
movement	O
restricted	O
to	O
a	O
2D	O
plane	O
.	O
</s>
<s>
The	O
game	O
was	O
conceived	O
as	O
a	O
smartphone-exclusive	O
spin-off	O
before	O
becoming	O
a	O
multiplatform	B-Operating_System
,	O
mainline	O
Sonic	B-Application
installment	O
.	O
</s>
<s>
As	O
a	O
continuation	O
of	O
the	O
Genesis	B-Operating_System
Sonic	B-Application
games	O
,	O
Episode	O
I	O
features	O
a	O
simple	O
control	O
scheme	O
,	O
no	O
voice	O
acting	O
,	O
level	O
design	O
emphasizing	O
platforming	O
and	O
momentum-based	O
gameplay	O
,	O
and	O
no	O
player	O
characters	O
besides	O
Sonic	B-Application
;	O
however	O
,	O
it	O
incorporates	O
Sonic	B-Application
's	O
design	O
and	O
abilities	O
from	O
later	O
games	O
like	O
Sonic	B-Application
Adventure	I-Application
(	O
1998	O
)	O
.	O
</s>
<s>
It	O
was	O
designed	O
to	O
appeal	O
to	O
both	O
older	O
Sonic	B-Application
fans	O
who	O
played	O
the	O
Genesis	B-Operating_System
games	O
and	O
newer	O
ones	O
who	O
played	O
more	O
recent	O
ones	O
like	O
Sonic	B-Application
Unleashed	I-Application
(	O
2008	O
)	O
.	O
</s>
<s>
Producer	O
Takashi	O
Iizuka	O
and	O
composer	O
Jun	O
Senoue	O
were	O
the	O
only	O
Sonic	B-Application
4	I-Application
developers	O
who	O
contributed	O
to	O
the	O
Genesis	B-Operating_System
games	O
.	O
</s>
<s>
Episode	O
I	O
was	O
released	O
in	O
October	O
2010	O
as	O
a	O
downloadable	O
game	O
for	O
iOS	B-Application
,	O
PlayStation	B-Operating_System
3	I-Operating_System
,	O
Wii	B-Operating_System
,	O
and	O
Xbox	B-Operating_System
360	I-Operating_System
.	O
</s>
<s>
Versions	O
for	O
Windows	B-Protocol
Phone	I-Protocol
,	O
Windows	O
,	O
Android	B-Application
,	O
and	O
BlackBerry	B-Application
Tablet	I-Application
OS	I-Application
followed	O
throughout	O
2011	O
and	O
2012	O
.	O
</s>
<s>
Critics	O
described	O
Episode	O
I	O
as	O
a	O
satisfying	O
return	O
to	O
classic	O
Sonic	B-Application
gameplay	O
and	O
praised	O
the	O
sense	O
of	O
nostalgia	B-Application
.	O
</s>
<s>
Criticism	O
was	O
directed	O
at	O
its	O
physics	O
engine	O
,	O
considered	O
inferior	O
to	O
that	O
of	O
the	O
Genesis	B-Operating_System
games	O
,	O
and	O
its	O
short	O
length	O
.	O
</s>
<s>
Episode	O
I	O
was	O
planned	O
as	O
the	O
first	O
episode	O
in	O
a	O
trilogy	O
;	O
Episode	B-Application
II	I-Application
was	O
released	O
in	O
May	O
2012	O
,	O
while	O
Episode	O
III	O
was	O
never	O
made	O
.	O
</s>
<s>
Sonic	B-Application
the	I-Application
Hedgehog	I-Application
4	I-Application
:	I-Application
Episode	I-Application
I	I-Application
is	O
a	O
side-scrolling	O
platform	O
game	O
similar	O
in	O
gameplay	O
and	O
style	O
to	O
the	O
1990s	O
Sonic	B-Application
the	I-Application
Hedgehog	I-Application
games	O
for	O
the	O
Sega	B-Operating_System
Genesis	I-Operating_System
.	O
</s>
<s>
The	O
story	O
begins	O
shortly	O
after	O
the	O
events	O
of	O
Sonic	B-Application
&	I-Application
Knuckles	I-Application
(	O
1994	O
)	O
.	O
</s>
<s>
Sonic	B-Application
the	I-Application
Hedgehog	I-Application
parts	O
with	O
his	O
friends	O
,	O
Miles	O
"	O
Tails	O
"	O
Prower	O
and	B-Application
Knuckles	I-Application
the	O
Echidna	O
,	O
to	O
explore	O
new	O
territories	O
on	O
his	O
own	O
.	O
</s>
<s>
However	O
,	O
series	O
antagonist	O
Doctor	O
Eggman	O
—	O
who	O
survived	O
his	O
defeat	O
in	O
Sonic	B-Application
&	I-Application
Knuckles	I-Application
—	O
resurfaces	O
,	O
refines	O
some	O
of	O
his	O
past	O
robots	O
,	O
and	O
initiates	O
a	O
plan	O
to	O
get	O
rid	O
of	O
Sonic	B-Application
.	O
</s>
<s>
Sonic	B-Application
4	I-Application
is	O
presented	O
from	O
a	O
2.5D	O
perspective	O
;	O
although	O
movement	O
is	O
restricted	O
to	O
a	O
2D	O
plane	O
,	O
characters	O
and	O
objects	O
are	O
rendered	O
in	O
3D	O
.	O
</s>
<s>
Sonic	B-Application
,	O
the	O
only	O
player	O
character	O
of	O
the	O
single-player	O
game	O
,	O
can	O
move	O
left	O
or	O
right	O
to	O
gain	O
speed	O
,	O
jump	O
,	O
and	O
roll	O
into	O
a	O
ball	O
to	O
attack	O
enemy	O
robots	O
.	O
</s>
<s>
Sonic	B-Application
can	O
also	O
perform	O
the	O
"	O
homing	O
attack	O
"	O
from	O
the	O
3D	O
Sonic	B-Application
games	O
;	O
when	O
in	O
midair	O
,	O
he	O
can	O
lock	O
on	O
to	O
robots	O
or	O
objects	O
and	O
home	O
in	O
on	O
them	O
.	O
</s>
<s>
Unlike	O
the	O
Genesis	B-Operating_System
Sonic	B-Application
games	O
,	O
after	O
completing	O
the	O
first	O
act	O
,	O
the	O
player	O
can	O
freely	O
choose	O
which	O
zone	O
to	O
play	O
via	O
a	O
world	O
map	O
.	O
</s>
<s>
The	O
levels	O
are	O
based	O
on	O
locations	O
from	O
the	O
original	O
Sonic	B-Application
the	I-Application
Hedgehog	I-Application
(	O
1991	O
)	O
and	O
Sonic	B-Application
the	I-Application
Hedgehog	I-Application
2	I-Application
(	O
1992	O
)	O
,	O
and	O
feature	O
elements	O
such	O
as	O
slopes	O
,	O
bottomless	O
pits	O
,	O
vertical	O
loops	O
,	O
corkscrews	O
,	O
springs	O
,	O
and	O
boost	O
pads	O
,	O
as	O
well	O
as	O
power-ups	O
like	O
shields	O
,	O
invincibility	O
,	O
and	O
speed	O
shoes	O
.	O
</s>
<s>
Some	O
levels	O
feature	O
unique	O
elements	O
,	O
like	O
vines	O
or	O
pinball	B-Application
flippers	O
and	O
bumpers	O
.	O
</s>
<s>
Like	O
other	O
Sonic	B-Application
games	O
,	O
Sonic	B-Application
collects	O
rings	O
as	O
a	O
form	O
of	O
health	O
:	O
if	O
the	O
player	O
is	O
in	O
possession	O
of	O
at	O
least	O
one	O
ring	O
and	O
is	O
hit	O
by	O
an	O
enemy	O
or	O
hazard	O
,	O
they	O
will	O
survive	O
,	O
but	O
their	O
rings	O
will	O
scatter	O
and	O
blink	O
before	O
disappearing	O
.	O
</s>
<s>
If	O
the	O
player	O
is	O
hit	O
with	O
no	O
rings	O
,	O
falls	O
in	O
a	O
pit	O
,	O
or	O
drowns	O
,	O
they	O
lose	O
a	O
life	O
,	O
and	O
will	O
receive	O
a	O
game	B-Application
over	I-Application
if	O
all	O
lives	O
are	O
lost	O
.	O
</s>
<s>
The	O
special	O
stages	O
in	O
Episode	O
I	O
are	O
based	O
on	O
those	O
from	O
Sonic	B-Application
the	I-Application
Hedgehog	I-Application
,	O
in	O
which	O
Sonic	B-Application
is	O
curled	O
in	O
a	O
ball	O
and	O
bounces	O
off	O
the	O
bumpers	O
and	O
walls	O
of	O
a	O
fully	O
rotating	O
maze	O
.	O
</s>
<s>
The	O
player	O
must	O
tilt	O
the	O
playing	O
field	O
to	O
navigate	O
Sonic	B-Application
through	O
the	O
maze	O
within	O
a	O
time	O
limit	O
,	O
collecting	O
rings	O
to	O
open	O
gates	O
and	O
time	O
bonuses	O
along	O
the	O
way	O
.	O
</s>
<s>
By	O
collecting	O
all	O
seven	O
,	O
the	O
player	O
unlocks	O
the	O
ability	O
to	O
transform	O
into	O
Super	O
Sonic	B-Application
,	O
granting	O
them	O
invincibility	O
and	O
increased	O
speed	O
at	O
the	O
cost	O
of	O
one	O
ring	O
a	O
second	O
.	O
</s>
<s>
Collecting	O
the	O
Chaos	O
Emeralds	O
also	O
unlocks	O
a	O
brief	O
post-credits	O
scene	O
that	O
shows	O
a	O
silhouette	O
of	O
Metal	O
Sonic	B-Application
,	O
teasing	O
the	O
events	O
of	O
Sonic	B-Application
the	I-Application
Hedgehog	I-Application
4	I-Application
:	I-Application
Episode	I-Application
II	I-Application
(	O
2012	O
)	O
.	O
</s>
<s>
For	O
instance	O
,	O
the	O
PlayStation	B-Operating_System
3	I-Operating_System
,	O
Xbox	B-Operating_System
360	I-Operating_System
,	O
and	O
Windows	O
versions	O
support	O
high-definition	O
and	O
widescreen	O
displays	O
,	O
whereas	O
the	B-Operating_System
Wii	I-Operating_System
version	O
does	O
not	O
.	O
</s>
<s>
Additionally	O
,	O
the	O
PlayStation	B-Operating_System
3	I-Operating_System
and	O
Wii	B-Operating_System
versions	O
both	O
support	O
their	O
systems	O
 '	O
respective	O
motion	B-Device
controllers	I-Device
.	O
</s>
<s>
The	O
mobile	B-Application
versions	O
can	O
be	O
controlled	O
with	O
either	O
the	O
accelerometers	O
or	O
virtual	O
buttons	O
on	O
the	O
touchscreen	B-Device
.	O
</s>
<s>
According	O
to	O
project	O
head	O
Takashi	O
Iizuka	O
,	O
Sonic	B-Application
4	I-Application
was	O
conceived	O
in	O
January	O
2009	O
;	O
development	O
began	O
four	O
months	O
later	O
and	O
lasted	O
about	O
a	O
year	O
and	O
a	O
half	O
.	O
</s>
<s>
Dimps	O
,	O
which	O
had	O
previously	O
developed	O
Sonic	B-Application
platformers	O
for	O
the	O
Game	B-Device
Boy	I-Device
Advance	I-Device
and	O
Nintendo	B-Device
DS	I-Device
,	O
led	O
development	O
,	O
with	O
assistance	O
from	O
Sonic	B-Application
Team	O
.	O
</s>
<s>
Sonic	B-Application
Team	O
's	O
Toshiyuki	O
Nagahara	O
served	O
as	O
director	O
.	O
</s>
<s>
The	O
only	O
developers	O
on	O
the	O
team	O
who	O
contributed	O
to	O
the	O
Genesis	B-Operating_System
games	O
were	O
producer	O
Iizuka	O
and	O
composer	O
Jun	O
Senoue	O
.	O
</s>
<s>
The	O
game	O
was	O
announced	O
on	O
September	O
11	O
,	O
2009	O
under	O
the	O
working	O
title	O
Project	B-Application
Needlemouse	I-Application
.	O
</s>
<s>
Its	O
proper	O
title	O
,	O
Sonic	B-Application
the	I-Application
Hedgehog	I-Application
4	I-Application
:	I-Application
Episode	I-Application
I	I-Application
,	O
was	O
revealed	O
on	O
February	O
4	O
,	O
2010	O
,	O
alongside	O
the	O
debut	O
of	O
in-game	O
footage	O
.	O
</s>
<s>
Brand	O
manager	O
Ken	O
Balough	O
stated	O
that	O
Sonic	B-Application
4	I-Application
was	O
conceived	O
following	O
fan	O
requests	O
for	O
a	O
return	O
to	O
classic	O
Sonic	B-Application
gameplay	O
.	O
</s>
<s>
He	O
acknowledged	O
the	O
divide	O
between	O
older	O
Sonic	B-Application
fans	O
who	O
played	O
the	O
Genesis	B-Operating_System
games	O
and	O
younger	O
ones	O
who	O
played	O
more	O
recent	O
games	O
like	O
Sonic	B-Application
Unleashed	I-Application
(	O
2008	O
)	O
,	O
and	O
said	O
Sega	O
needed	O
to	O
cater	O
to	O
both	O
demographics	O
.	O
</s>
<s>
In	O
an	O
interview	O
with	O
Nintendo	O
Life	O
,	O
Balough	O
said	O
that	O
"[w]hen	O
we	O
started	O
discussing	O
doing	O
a	O
2D	O
Sonic	B-Application
game	O
,	O
it	O
just	O
made	O
sense	O
that	O
we	O
would	O
make	O
Sonic	B-Application
4	I-Application
.	O
</s>
<s>
While	O
Balough	O
said	O
the	O
game	O
was	O
always	O
called	O
Sonic	B-Application
4	I-Application
,	O
according	O
to	O
journalist	O
Kurt	O
Kalata	O
,	O
Sonic	B-Application
4	I-Application
was	O
not	O
conceived	O
as	O
a	O
mainline	O
,	O
numbered	O
Sonic	B-Application
game	O
,	O
but	O
rather	O
as	O
a	O
smartphone-exclusive	O
spin-off	O
called	O
Sonic	B-Application
the	O
Portable	O
that	O
took	O
advantage	O
of	O
those	O
devices	O
 '	O
gyroscope	B-Application
functions	O
.	O
</s>
<s>
Kalata	O
wrote	O
that	O
it	O
was	O
retitled	O
Sonic	B-Application
4	I-Application
at	O
the	O
behest	O
of	O
Sega	O
's	O
American	O
branch	O
and	O
made	O
a	O
multiplatform	B-Operating_System
release	O
,	O
and	O
noted	O
that	O
one	O
of	O
the	O
game	O
's	O
levels	O
still	O
features	O
signs	O
that	O
say	O
Sonic	B-Application
the	O
Portable	O
.	O
</s>
<s>
Iizuka	O
noted	O
that	O
after	O
Sonic	B-Application
Adventure	I-Application
was	O
released	O
in	O
1998	O
,	O
the	O
Sonic	B-Application
series	I-Application
began	O
to	O
have	O
a	O
greater	O
emphasis	O
on	O
speed	O
.	O
</s>
<s>
However	O
,	O
he	O
also	O
acknowledged	O
many	O
fans	O
still	O
enjoyed	O
the	O
Genesis	B-Operating_System
games	O
,	O
as	O
evidenced	O
from	O
their	O
popularity	O
on	O
digital	O
distribution	O
platforms	O
.	O
</s>
<s>
With	O
Sonic	B-Application
4	I-Application
,	O
Iizuka	O
was	O
motivated	O
to	O
return	O
to	O
the	O
classic	O
Sonic	B-Application
style	O
with	O
modern	O
technologies	O
.	O
</s>
<s>
To	O
stay	O
faithful	O
to	O
the	O
original	O
Genesis	B-Operating_System
games	O
,	O
the	O
developers	O
chose	O
not	O
to	O
include	O
voice	O
acting	O
.	O
</s>
<s>
The	O
team	O
began	O
development	O
using	O
elements	O
they	O
considered	O
vital	O
to	O
the	O
Sonic	B-Application
series	I-Application
:	O
a	O
simple	O
control	O
scheme	O
—	O
with	O
jumping	O
and	O
attacking	O
controlled	O
by	O
a	O
single	O
button	O
—	O
and	O
level	O
design	O
emphasizing	O
platforming	O
and	O
momentum-based	O
gameplay	O
.	O
</s>
<s>
To	O
establish	O
Episode	O
I	O
as	O
a	O
successor	O
to	O
the	O
Genesis	B-Operating_System
games	O
,	O
the	O
developers	O
chose	O
to	O
revive	O
those	O
games	O
 '	O
level	O
locales	O
to	O
,	O
as	O
Iizuka	O
explained	O
,	O
"	O
tap	O
into	O
that	O
nostalgia	B-Application
factor	O
.	O
</s>
<s>
Essentially	O
we	O
wanted	O
people	O
to	O
recognize	O
this	O
was	O
a	O
continuation	O
from	O
the	O
 [ Genesis ] 	O
era	O
Sonics.	O
"	O
</s>
<s>
While	O
the	O
content	O
in	O
all	O
versions	O
is	O
mostly	O
the	O
same	O
,	O
two	O
levels	O
in	O
the	O
mobile	B-Application
version	O
were	O
replaced	O
in	O
the	O
console	O
releases	O
.	O
</s>
<s>
These	O
two	O
levels	O
were	O
supposed	O
to	O
be	O
retained	O
across	O
all	O
releases	O
,	O
but	O
they	O
were	O
designed	O
around	O
the	O
use	O
of	O
a	O
smartphone	B-Application
gyroscope	B-Application
,	O
and	O
the	O
team	O
did	O
not	O
think	O
they	O
translated	O
well	O
to	O
a	O
console	O
.	O
</s>
<s>
One	O
new	O
addition	O
was	O
Sonic	B-Application
's	O
homing	O
attack	O
from	O
Sonic	B-Application
Adventure	I-Application
;	O
Iizuka	O
said	O
the	O
team	O
"	O
wanted	O
to	O
add	O
that	O
excitement	O
of	O
performing	O
continuous	O
attacks	O
"	O
and	O
felt	O
it	O
"add[ed]	O
to	O
the	O
classic-style	O
gameplay	O
by	O
providing	O
a	O
new	O
means	O
to	O
discover	O
routes	O
in	O
the	O
sky	O
"	O
.	O
</s>
<s>
Though	O
a	O
return	O
to	O
the	O
classic	O
Sonic	B-Application
formula	O
,	O
Sonic	B-Application
the	I-Application
Hedgehog	I-Application
4	I-Application
:	I-Application
Episode	I-Application
I	I-Application
does	O
not	O
reuse	O
Sonic	B-Application
's	O
original	O
design	O
,	O
instead	O
retaining	O
his	O
post-Adventure	O
design	O
.	O
</s>
<s>
When	O
fans	O
answered	O
trivia	O
questions	O
,	O
the	O
list	O
got	O
whittled	O
down	O
,	O
and	O
culminated	O
with	O
the	O
reveal	O
that	O
Sonic	B-Application
would	O
be	O
the	O
only	O
playable	O
character	O
.	O
</s>
<s>
Despite	O
this	O
,	O
the	O
post-credits	O
scene	O
teases	O
the	O
reintroduction	O
of	O
Metal	O
Sonic	B-Application
,	O
who	O
had	O
not	O
appeared	O
in	O
a	O
Sonic	B-Application
game	O
for	O
years	O
.	O
</s>
<s>
Balough	O
stated	O
that	O
fans	O
had	O
been	O
asking	O
Sega	O
to	O
bring	O
back	O
Metal	O
Sonic	B-Application
for	O
years	O
,	O
and	O
that	O
the	O
post-credits	O
scene	O
was	O
added	O
to	O
keep	O
players	O
excited	O
for	O
Episode	B-Application
II	I-Application
.	O
</s>
<s>
Senoue	O
only	O
composed	O
some	O
tracks	O
for	O
the	O
Genesis	B-Operating_System
Sonic	B-Application
games	O
,	O
but	O
for	O
Sonic	B-Application
4	I-Application
,	O
he	O
was	O
responsible	O
for	O
creating	O
all	O
the	O
music	O
and	O
sound	O
effects	O
.	O
</s>
<s>
The	O
music	O
was	O
written	O
to	O
replicate	O
the	O
style	O
of	O
the	O
Genesis	B-Operating_System
Sonic	B-Application
games	O
because	O
,	O
according	O
to	O
Balough	O
,	O
the	O
developers	O
wanted	O
the	O
game	O
to	O
feel	O
"	O
like	O
a	O
genuine	O
extension	O
of	O
the	O
first	O
three	O
Sonic	B-Application
games	O
"	O
.	O
</s>
<s>
Senoue	O
said	O
that	O
he	O
attempted	O
to	O
compose	O
the	O
tracks	O
as	O
if	O
he	O
had	O
been	O
composing	O
them	O
for	O
the	O
Genesis	B-Operating_System
,	O
using	O
as	O
few	O
notes	O
as	O
possible	O
.	O
</s>
<s>
He	O
did	O
not	O
use	O
any	O
FM	O
sound	O
tapes	O
,	O
although	O
he	O
did	O
unsuccessfully	O
attempt	O
to	O
find	O
an	O
old	O
Genesis	B-Operating_System
development	O
kit	O
.	O
</s>
<s>
Senoue	O
attempted	O
to	O
compose	O
tracks	O
"	O
with	O
a	O
similar	O
beat	O
or	O
similar	O
tempo	O
"	O
to	O
those	O
from	O
Sonic	B-Application
the	I-Application
Hedgehog	I-Application
and	O
Sonic	B-Application
the	I-Application
Hedgehog	I-Application
2	I-Application
.	O
</s>
<s>
Eggman	O
's	O
theme	O
in	O
Episode	O
I	O
had	O
originally	O
been	O
composed	O
for	O
Sonic	B-Application
3D	I-Application
Blast	I-Application
(	O
1996	O
)	O
,	O
but	O
went	O
unused	O
in	O
that	O
game	O
.	O
</s>
<s>
Months	O
before	O
the	O
game	O
's	O
release	O
,	O
a	O
prototype	B-Application
version	O
was	O
made	O
available	O
to	O
users	O
of	O
the	B-Operating_System
Xbox	I-Operating_System
360	I-Operating_System
's	O
game	O
testing	O
service	O
PartnerNet	O
.	O
</s>
<s>
In	O
May	O
2010	O
,	O
Sega	O
announced	O
that	O
Episode	O
I	O
had	O
been	O
delayed	O
to	O
late	O
2010	O
in	O
response	O
to	O
both	O
internal	O
and	O
fan	O
feedback	O
;	O
Iizuka	O
later	O
clarified	O
that	O
the	O
delay	O
was	O
done	O
so	O
the	O
developers	O
could	O
replace	O
the	O
mobile-exclusive	O
levels	O
with	O
ones	O
better	O
suited	O
for	O
consoles	O
.	O
</s>
<s>
Episode	O
I	O
was	O
released	O
on	O
October	O
7	O
,	O
2010	O
,	O
for	O
iOS	B-Application
.	O
</s>
<s>
Releases	O
for	O
other	O
platforms	O
soon	O
followed	O
:	O
the	B-Operating_System
Wii	I-Operating_System
version	O
was	O
released	O
via	O
WiiWare	O
in	O
North	O
America	O
on	O
October	O
11	O
and	O
in	O
Europe	O
on	O
October	O
15	O
;	O
the	O
PlayStation	B-Operating_System
3	I-Operating_System
version	O
was	O
released	O
via	O
PlayStation	B-Device
Network	I-Device
in	O
North	O
America	O
on	O
October	O
12	O
and	O
in	O
Europe	O
on	O
October	O
13	O
;	O
and	O
the	B-Operating_System
Xbox	I-Operating_System
360	I-Operating_System
version	O
was	O
released	O
via	O
Xbox	B-Device
Live	I-Device
Arcade	I-Device
on	O
October	O
13	O
.	O
</s>
<s>
Other	O
releases	O
included	O
a	O
Windows	B-Protocol
Phone	I-Protocol
version	O
on	O
June	O
15	O
,	O
2011	O
;	O
a	O
Windows	O
version	O
via	O
Steam	B-Application
on	O
January	O
19	O
,	O
2012	O
;	O
an	O
Android	B-Application
version	O
on	O
January	O
25	O
,	O
2012	O
;	O
and	O
a	O
BlackBerry	B-Application
Tablet	I-Application
OS	I-Application
version	O
on	O
July	O
20	O
,	O
2012	O
.	O
</s>
<s>
Additionally	O
,	O
both	O
Episode	O
I	O
and	O
Episode	B-Application
II	I-Application
were	O
released	O
for	O
the	O
Android-powered	O
Ouya	B-Application
on	O
July	O
9	O
,	O
2013	O
.	O
</s>
<s>
In	O
April	O
2016	O
,	O
the	O
iOS	B-Application
version	O
was	O
updated	O
for	O
the	O
first	O
time	O
in	O
three	O
years	O
to	O
modernize	O
it	O
for	O
newer	O
devices	O
.	O
</s>
<s>
Changes	O
included	O
support	O
for	O
widescreen	O
and	O
Retina	B-Operating_System
displays	I-Operating_System
,	O
more	O
detailed	O
character	O
models	O
,	O
and	O
refined	O
textures	O
.	O
</s>
<s>
The	O
iOS	B-Application
version	O
was	O
initially	O
split	O
into	O
separate	O
versions	O
for	O
iPhone	B-Device
and	O
iPad	B-Device
;	O
the	O
update	O
discontinued	O
the	O
iPad	B-Device
version	O
and	O
made	O
the	O
iPhone	B-Device
one	O
a	O
"	O
universal	O
"	O
application	O
,	O
meaning	O
it	O
works	O
across	O
all	O
iOS	B-Application
devices	O
.	O
</s>
<s>
Later	O
in	O
2016	O
,	O
the	B-Operating_System
Xbox	I-Operating_System
360	I-Operating_System
versions	O
of	O
Episode	O
I	O
and	O
Episode	B-Application
II	I-Application
were	O
added	O
to	O
the	B-Device
Xbox	I-Device
One	I-Device
's	O
catalog	O
of	O
backward	B-Device
compatible	I-Device
games	O
.	O
</s>
<s>
According	O
to	O
review	B-Application
aggregator	I-Application
Metacritic	O
,	O
the	B-Operating_System
Wii	I-Operating_System
version	O
received	O
"	O
generally	O
favorable	O
reviews	O
"	O
,	O
while	O
the	O
both	O
iOS	B-Application
and	O
other	O
console	O
versions	O
received	O
"	O
mixed	O
or	O
average	O
reviews	O
"	O
.	O
</s>
<s>
GameTrailers	O
gave	O
it	O
a	O
7.5	O
,	O
calling	O
it	O
a	O
worthy	O
investment	O
for	O
Sonic	B-Application
fans	O
.	O
</s>
<s>
The	O
game	O
's	O
physics	O
were	O
met	O
with	O
major	O
criticism	O
,	O
with	O
the	O
general	O
consensus	O
being	O
that	O
they	O
were	O
inferior	O
to	O
the	O
momentum-based	O
physics	O
from	O
the	O
Genesis	B-Operating_System
games	O
.	O
</s>
<s>
On	O
YouTube	B-General_Concept
,	O
hundreds	O
of	O
gameplay	O
videos	O
were	O
posted	O
by	O
fans	O
showcasing	O
several	O
oddities	O
.	O
</s>
<s>
Shortly	O
before	O
Episode	O
I	O
release	O
,	O
Balough	O
confirmed	O
that	O
Sega	O
had	O
planned	O
the	O
entire	O
Sonic	B-Application
4	I-Application
story	O
.	O
</s>
<s>
After	O
completing	O
them	O
all	O
,	O
you	O
'll	O
have	O
experienced	O
a	O
larger	O
overall	O
story	O
arc	O
that	O
lives	O
up	O
to	O
the	O
epic	O
nature	O
of	O
earlier	O
Sonics.	O
"	O
</s>
<s>
In	O
August	O
2011	O
,	O
Iizuka	O
stated	O
that	O
Episode	B-Application
II	I-Application
would	O
not	O
be	O
released	O
until	O
2012	O
(	O
over	O
a	O
year	O
after	O
Episode	O
I	O
)	O
so	O
Sonic	B-Application
Team	O
could	O
focus	O
on	O
Sonic	B-Application
Generations	I-Application
.	O
</s>
<s>
Ahead	O
of	O
Episode	B-Application
II	I-Application
,	O
Sega	O
rereleased	O
Sonic	B-Application
CD	I-Application
(	O
1993	O
)	O
for	O
modern	O
consoles	O
,	O
and	O
advertised	O
it	O
as	O
a	O
prequel	O
to	O
Sonic	B-Application
4	I-Application
.	O
</s>
<s>
Episode	B-Application
II	I-Application
,	O
released	O
in	O
May	O
2012	O
,	O
reintroduces	O
Tails	O
and	O
Metal	O
Sonic	B-Application
,	O
and	O
follows	O
Sonic	B-Application
and	O
Tails	O
as	O
they	O
attempt	O
to	O
prevent	O
Eggman	O
and	O
Metal	O
Sonic	B-Application
from	O
relaunching	O
the	O
Death	O
Egg	O
.	O
</s>
<s>
Fan	O
input	O
from	O
Episode	O
I	O
played	O
a	O
significant	O
role	O
in	O
the	O
development	O
of	O
Episode	B-Application
II	I-Application
,	O
as	O
the	O
developers	O
worked	O
to	O
address	O
aspects	O
fans	O
took	O
issue	O
with	O
,	O
such	O
as	O
the	O
physics	O
engine	O
.	O
</s>
<s>
Episode	B-Application
II	I-Application
was	O
released	O
on	O
most	O
platforms	O
that	O
Episode	O
I	O
was	O
available	O
on	O
,	O
although	O
the	B-Operating_System
Wii	I-Operating_System
version	O
was	O
canceled	O
due	O
to	O
hardware	O
constraints	O
.	O
</s>
<s>
Players	O
who	O
own	O
both	O
episodes	O
on	O
a	O
single	O
platform	O
unlock	O
the	O
ability	O
to	O
play	O
as	O
Metal	O
Sonic	B-Application
in	O
Episode	O
I	O
levels	O
.	O
</s>
<s>
In	O
March	O
2012	O
,	O
Iizuka	O
announced	O
that	O
Sega	O
did	O
not	O
plan	O
to	O
continue	O
Sonic	B-Application
4	I-Application
beyond	O
Episode	B-Application
II	I-Application
.	O
</s>
<s>
In	O
2015	O
,	O
Australian	O
developer	O
Christian	O
Whitehead	O
said	O
that	O
he	O
had	O
been	O
offered	O
the	O
opportunity	O
to	O
develop	O
Episode	O
III	O
with	O
Sega	O
Studios	O
Australia	O
before	O
that	O
division	O
was	O
shut	O
down	O
,	O
and	O
he	O
instead	O
worked	O
on	O
remasters	O
of	O
Sonic	B-Application
the	I-Application
Hedgehog	I-Application
and	O
Sonic	B-Application
the	I-Application
Hedgehog	I-Application
2	I-Application
between	O
2012	O
and	O
2013	O
.	O
</s>
<s>
Whitehead	O
would	O
go	O
on	O
to	O
lead	O
the	O
development	O
of	O
Sonic	B-Application
Mania	I-Application
(	O
2017	O
)	O
,	O
which	O
,	O
like	O
Sonic	B-Application
4	I-Application
,	O
acts	O
as	O
a	O
sequel	O
to	O
the	O
Genesis	B-Operating_System
Sonic	B-Application
games	O
.	O
</s>
<s>
Sonic	B-Application
4	I-Application
and	O
Sonic	B-Application
Mania	I-Application
were	O
frequently	O
compared	O
,	O
with	O
journalists	O
viewing	O
Sonic	B-Application
4	I-Application
unfavorably	O
in	O
contrast	O
to	O
Mania	O
.	O
</s>
