<s>
Sunless	B-Application
Skies	I-Application
is	O
a	O
role-playing	O
video	O
game	O
developed	O
by	O
Failbetter	O
Games	O
.	O
</s>
<s>
Sunless	B-Application
Skies	I-Application
is	O
a	O
direct	O
sequel	O
to	O
2015	O
's	O
Sunless	B-Application
Sea	I-Application
and	O
incorporates	O
similar	O
elements	O
and	O
setting	O
.	O
</s>
<s>
Sunless	B-Application
Skies	I-Application
is	O
an	O
exploration	O
and	O
narrative	O
focused	O
role-playing	O
video	O
game	O
.	O
</s>
<s>
Sunless	B-Application
Skies	I-Application
is	O
set	O
in	O
the	O
same	O
Victorian	O
era-inspired	O
world	O
as	O
Fallen	B-Application
London	I-Application
and	O
Sunless	B-Application
Sea	I-Application
.	O
</s>
<s>
The	O
game	O
is	O
set	O
ten	O
years	O
after	O
the	O
events	O
of	O
Sunless	B-Application
Sea	I-Application
,	O
after	O
the	O
subterranean	O
city	O
of	O
London	O
opened	O
a	O
gateway	O
known	O
as	O
the	O
Avid	O
Horizon	O
and	O
gained	O
access	O
to	O
outer	O
space	O
,	O
here	O
called	O
the	O
High	O
Wilderness	O
,	O
where	O
stars	O
are	O
godlike	O
beings	O
who	O
exert	O
power	O
through	O
their	O
light	O
and	O
unspeakable	O
terrors	O
lurk	O
in	O
the	O
dark	O
.	O
</s>
<s>
The	O
game	O
was	O
developed	O
on	O
the	O
Unity	B-Application
game	I-Application
engine	I-Application
and	O
Failbetter	O
's	O
own	O
narrative	O
platform	O
StoryNexus	O
.	O
</s>
<s>
Failbetter	O
CEO	O
Paul	O
Arendt	O
noted	O
that	O
they	O
did	O
n't	O
want	O
a	O
sequel	O
to	O
just	O
be	O
Sunless	B-Application
Sea	I-Application
2	O
with	O
bigger	O
ships	O
.	O
</s>
<s>
The	O
development	O
team	O
cited	O
the	O
science	O
fiction	O
and	O
planetary	O
romance	O
works	O
of	O
authors	O
C	O
.	O
S	O
.	O
Lewis	O
,	O
H	O
.	O
G	O
.	O
Wells	O
,	O
and	O
Leigh	O
Brackett	O
as	O
influences	O
along	O
with	O
Art	O
Nouveau	O
and	O
the	O
1999	O
game	O
Planescape	B-Application
:	I-Application
Torment	I-Application
.	O
</s>
<s>
The	O
game	O
was	O
scheduled	O
to	O
be	O
released	O
in	O
early	O
access	O
in	O
May	O
2017	O
with	O
a	O
full	O
release	O
in	O
May	O
2018	O
,	O
for	O
Linux	B-Application
,	O
macOS	B-Application
,	O
Windows-based	O
personal	B-Device
computers	I-Device
.	O
</s>
<s>
Failbetter	O
announced	O
on	O
19	O
October	O
2019	O
that	O
the	O
final	O
update	O
for	O
Sunless	B-Application
Skies	I-Application
would	O
be	O
Sunless	B-Application
Skies	I-Application
:	I-Application
Sovereign	I-Application
Edition	I-Application
,	O
a	O
definitive	O
version	O
of	O
the	O
game	O
containing	O
all	O
previous	O
content	O
in	O
addition	O
to	O
several	O
new	O
narrative	O
events	O
and	O
gameplay	O
improvements	O
.	O
</s>
<s>
Owners	O
of	O
the	O
PC	O
version	O
of	O
the	O
game	O
will	O
receive	O
the	O
Sovereign	O
Edition	O
update	O
for	O
free	O
,	O
and	O
the	O
full	O
game	O
with	O
all	O
post-launch	O
updates	O
included	O
will	O
be	O
released	O
simultaneously	O
on	O
PlayStation	B-Operating_System
4	I-Operating_System
,	O
Xbox	B-Device
One	I-Device
,	O
and	O
Nintendo	B-Application
Switch	I-Application
.	O
</s>
<s>
Sunless	B-Application
Skies	I-Application
:	I-Application
Sovereign	I-Application
Edition	I-Application
was	O
released	O
on	O
19	O
May	O
2021	O
.	O
</s>
<s>
Upon	O
the	O
game	O
's	O
release	O
in	O
January	O
2019	O
,	O
Sunless	B-Application
Skies	I-Application
was	O
praised	O
by	O
critics	O
,	O
receiving	O
a	O
Metacritic	O
score	O
of	O
87	O
,	O
indicating	O
'	O
generally	O
favourable	O
 '	O
reviews	O
.	O
</s>
