<s>
Hollow	B-Device
Knight	I-Device
is	O
a	O
2017	O
Metroidvania	O
video	O
game	O
developed	O
and	O
published	O
by	O
independent	O
developer	O
Team	B-Device
Cherry	I-Device
.	O
</s>
<s>
The	O
concept	O
behind	O
Hollow	B-Device
Knight	I-Device
was	O
originally	O
conceived	O
in	O
2013	O
in	O
the	O
Ludum	O
Dare	O
game	O
jam	O
.	O
</s>
<s>
Team	B-Device
Cherry	I-Device
wanted	O
to	O
create	O
a	O
game	O
inspired	O
by	O
older	O
platformers	O
that	O
replicated	O
the	O
explorational	O
aspects	O
of	O
its	O
influences	O
.	O
</s>
<s>
Inspirations	O
for	O
the	O
game	O
include	O
Faxanadu	B-Application
,	O
Metroid	B-Device
,	O
Zelda	B-Application
II	I-Application
:	I-Application
The	I-Application
Adventure	I-Application
of	I-Application
Link	I-Application
,	O
and	O
Mega	B-Application
Man	I-Application
X	I-Application
.	O
</s>
<s>
It	O
was	O
released	O
for	O
Windows	O
,	O
Linux	B-Application
,	O
and	O
macOS	B-Application
,	O
in	O
early	O
2017	O
and	O
for	O
the	O
Nintendo	B-Application
Switch	I-Application
,	O
PlayStation	B-Operating_System
4	I-Operating_System
,	O
and	O
Xbox	B-Device
One	I-Device
in	O
2018	O
.	O
</s>
<s>
After	O
release	O
,	O
Team	B-Device
Cherry	I-Device
supported	O
the	O
game	O
with	O
four	O
free	O
expansions	B-Protocol
.	O
</s>
<s>
Hollow	B-Device
Knight	I-Device
was	O
well	O
received	O
by	O
critics	O
,	O
with	O
particular	O
praise	O
for	O
its	O
music	O
,	O
art	O
style	O
,	O
worldbuilding	O
,	O
atmosphere	O
,	O
combat	O
and	O
level	O
of	O
difficulty	O
.	O
</s>
<s>
A	O
sequel	O
,	O
Hollow	B-Application
Knight	I-Application
:	I-Application
Silksong	I-Application
,	O
is	O
currently	O
in	O
development	O
.	O
</s>
<s>
Hollow	B-Device
Knight	I-Device
is	O
a	O
2D	O
side-scrolling	O
Metroidvania	O
game	O
that	O
takes	O
place	O
in	O
Hallownest	O
,	O
a	O
fictional	O
underground	O
kingdom	O
.	O
</s>
<s>
In	O
this	O
mode	O
,	O
dying	B-Application
is	I-Application
permanent	I-Application
,	O
i.e.	O
</s>
<s>
With	O
its	O
nonlinear	O
gameplay	O
design	O
,	O
Hollow	B-Device
Knight	I-Device
does	O
not	O
bind	O
the	O
player	O
to	O
one	O
path	O
through	O
the	O
game	O
nor	O
require	O
them	O
to	O
explore	O
the	O
whole	O
world	O
,	O
there	O
are	O
entire	O
places	O
that	O
can	O
be	O
missed	O
when	O
finishing	O
the	O
game	O
,	O
though	O
there	O
are	O
obstacles	O
that	O
limit	O
the	O
player	O
's	O
access	O
to	O
various	O
areas	O
.	O
</s>
<s>
As	O
the	O
Knight	O
ventures	O
through	O
the	O
ruins	O
,	O
they	O
learn	O
that	O
Hallownest	O
was	O
once	O
a	O
flourishing	O
kingdom	O
which	O
fell	O
after	O
becoming	O
overrun	O
with	O
"	O
The	O
Infection	O
"	O
,	O
a	O
supernatural	O
disease	O
that	O
drove	O
the	O
kingdom	O
's	O
citizens	O
to	O
madness	B-Operating_System
and	O
undeath	O
.	O
</s>
<s>
The	O
Pale	O
King	O
chose	O
a	O
Vessel	O
known	O
as	O
the	B-Device
Hollow	I-Device
Knight	I-Device
to	O
trap	O
the	O
Radiance	O
,	O
leaving	O
the	O
rest	O
locked	O
in	O
a	O
Void-covered	O
pit	O
called	O
the	O
Abyss	O
.	O
</s>
<s>
After	O
the	B-Device
Hollow	I-Device
Knight	I-Device
was	O
locked	O
within	O
the	O
Temple	O
of	O
the	O
Black	O
Egg	O
,	O
the	O
Radiance	O
persisted	O
within	O
the	O
Vessel	O
,	O
weakening	O
the	O
temple	O
's	O
seals	O
and	O
allowing	O
the	O
Infection	O
to	O
escape	O
.	O
</s>
<s>
Inside	O
,	O
they	O
encounter	O
and	O
battle	O
with	O
the	O
infected	O
Hollow	B-Device
Knight	I-Device
.	O
</s>
<s>
These	O
endings	O
include	O
the	O
Knight	O
defeating	O
the	O
infected	O
Hollow	B-Device
Knight	I-Device
and	O
taking	O
its	O
place	O
containing	O
the	O
Radiance	O
,	O
defeating	O
the	B-Device
Hollow	I-Device
Knight	I-Device
with	O
Hornet	O
's	O
assistance	O
,	O
or	O
using	O
the	O
Void	O
Heart	O
item	O
to	O
directly	O
fight	O
and	O
defeat	O
the	O
Radiance	O
inside	O
the	O
Dream	O
Realm	O
.	O
</s>
<s>
In	O
the	O
second	O
expansion	O
to	O
Hollow	B-Device
Knight	I-Device
,	O
the	O
Knight	O
lights	O
a	O
"	O
Nightmare	O
Lantern	O
"	O
found	O
hidden	O
in	O
the	O
Howling	O
Cliffs	O
after	O
using	O
the	O
Dream	O
Nail	O
on	O
a	O
masked	O
bug	O
.	O
</s>
<s>
The	O
lantern	O
summons	O
a	O
mysterious	O
group	O
of	O
circus	O
performers	O
to	O
Dirtmouth	O
,	O
who	O
identify	O
themselves	O
as	O
the	B-Device
Grimm	I-Device
Troupe	I-Device
.	O
</s>
<s>
More	O
content	O
was	O
added	O
to	O
Hollow	B-Device
Knight	I-Device
with	O
the	O
fourth	O
and	O
final	O
expansion	O
,	O
Godmaster	B-Device
,	O
in	O
which	O
the	O
Knight	O
can	O
battle	O
harder	O
versions	O
of	O
all	O
of	O
the	O
bosses	O
in	O
the	O
game	O
through	O
a	O
series	O
of	O
challenges	O
.	O
</s>
<s>
The	O
idea	O
that	O
prompted	O
the	O
creation	O
of	O
Hollow	B-Device
Knight	I-Device
originated	O
in	O
a	O
game	O
jam	O
,	O
Ludum	O
Dare	O
2013	O
,	O
in	O
which	O
two	O
of	O
the	O
game	O
's	O
developers	O
,	O
Ari	O
Gibson	O
and	O
William	O
Pellen	O
,	O
developed	O
a	O
game	O
called	O
Hungry	O
Knight	O
,	O
in	O
which	O
the	O
character	O
that	O
would	O
later	O
become	O
the	O
Knight	O
kills	O
bugs	O
to	O
stave	O
off	O
starvation	O
.	O
</s>
<s>
The	O
game	O
,	O
considered	O
"	O
not	O
very	O
good	O
"	O
,	O
used	O
to	O
hold	O
a	O
1/5	O
star	O
rating	O
on	O
Newgrounds	B-Operating_System
,	O
but	O
has	O
since	O
increased	O
to	O
4/5	O
.	O
</s>
<s>
Influences	O
for	O
the	O
game	O
include	O
Faxanadu	B-Application
,	O
Metroid	B-Device
,	O
Zelda	B-Application
II	I-Application
,	O
and	O
Mega	B-Application
Man	I-Application
X	I-Application
.	O
</s>
<s>
Team	B-Device
Cherry	I-Device
noted	O
that	O
Hallownest	O
was	O
in	O
some	O
ways	O
the	O
inverse	O
of	O
the	O
world	O
tree	O
setting	O
in	O
Faxanadu	B-Application
.	O
</s>
<s>
Believing	O
that	O
control	O
of	O
the	O
character	O
was	O
most	O
important	O
for	O
the	O
player	O
's	O
enjoyment	O
of	O
the	O
game	O
,	O
the	O
developers	O
based	O
the	O
Knight	O
's	O
movement	O
on	O
Mega	B-Application
Man	I-Application
X	I-Application
.	O
</s>
<s>
The	O
complexity	O
of	O
the	O
world	O
was	O
based	O
on	O
Metroid	B-Device
,	O
which	O
allows	O
players	O
to	O
become	O
disoriented	O
and	O
lost	O
,	O
focusing	O
on	O
the	O
enjoyment	O
of	O
finding	O
one	O
's	O
way	O
.	O
</s>
<s>
Hollow	B-Device
Knight	I-Device
was	O
revealed	O
on	O
Kickstarter	O
in	O
November	O
2014	O
,	O
seeking	O
a	O
"	O
modest	O
"	O
sum	O
of	O
.	O
</s>
<s>
The	O
game	O
reached	O
a	O
beta	O
state	O
in	O
September	O
2015	O
and	O
continued	O
to	O
achieve	O
numerous	O
stretch	O
goals	O
to	O
add	O
in	O
more	O
content	O
after	O
an	O
engine	O
switch	O
from	O
Stencyl	B-Application
to	O
Unity	B-Application
.	O
</s>
<s>
Hollow	B-Device
Knight	I-Device
was	O
officially	O
released	O
for	O
Windows	O
on	O
24	O
February	O
2017	O
,	O
with	O
versions	O
for	O
Linux	B-Application
and	O
macOS	B-Application
being	O
released	O
on	O
11	O
April	O
of	O
the	O
same	O
year	O
.	O
</s>
<s>
The	O
Nintendo	B-Application
Switch	I-Application
version	O
of	O
Hollow	B-Device
Knight	I-Device
was	O
announced	O
in	O
January	O
2017	O
and	O
released	O
on	O
12	O
June	O
2018	O
.	O
</s>
<s>
Team	B-Device
Cherry	I-Device
originally	O
planned	O
to	O
make	O
their	O
game	O
available	O
on	O
the	O
Wii	B-Device
U	I-Device
.	O
</s>
<s>
Development	O
of	O
the	O
Wii	B-Device
U	I-Device
version	O
began	O
in	O
2016	O
,	O
alongside	O
the	O
PC	O
version	O
,	O
and	O
it	O
eventually	O
shifted	O
to	O
Switch	O
.	O
</s>
<s>
The	O
creators	O
of	O
Hollow	B-Device
Knight	I-Device
worked	O
with	O
another	O
Australian	O
developer	O
,	O
Shark	O
Jump	O
Studios	O
,	O
to	O
speed	O
up	O
the	O
porting	O
process	O
.	O
</s>
<s>
Initially	O
,	O
Team	B-Device
Cherry	I-Device
planned	O
the	O
Switch	O
version	O
to	O
arrive	O
"	O
not	O
too	O
long	O
after	O
the	O
platform	O
's	O
launch	O
"	O
;	O
subsequently	O
they	O
delayed	O
it	O
to	O
early	O
2018	O
.	O
</s>
<s>
A	O
release	O
date	O
was	O
not	O
announced	O
until	O
the	O
Nintendo	O
Direct	O
presentation	O
at	O
E3	O
2018	O
on	O
12	O
June	O
2018	O
,	O
when	O
it	O
was	O
unveiled	O
the	O
game	O
would	O
be	O
available	O
later	O
that	O
day	O
via	O
Nintendo	B-Application
eShop	I-Application
.	O
</s>
<s>
Versions	O
for	O
PlayStation	B-Operating_System
4	I-Operating_System
and	O
Xbox	B-Device
One	I-Device
were	O
released	O
as	O
Hollow	B-Device
Knight	I-Device
:	O
Voidheart	O
Edition	O
on	O
25	O
September	O
2018	O
.	O
</s>
<s>
An	O
official	O
Hollow	B-Device
Knight	I-Device
Piano	O
Collections	O
sheet	O
music	O
book	O
and	O
album	O
was	O
released	O
in	O
2019	O
by	O
video	O
game	O
music	O
label	O
Materia	O
Collective	O
,	O
arranged	O
by	O
David	O
Peacock	O
and	O
performed	O
by	O
Augustine	O
Mayuga	O
Gonzales	O
.	O
</s>
<s>
On	O
3	O
August	O
2017	O
,	O
the	O
"	O
Hidden	O
Dreams	O
"	O
DLC	B-Protocol
was	O
released	O
,	O
featuring	O
two	O
new	O
optional	O
boss	O
encounters	O
,	O
two	O
new	O
songs	O
in	O
the	O
soundtrack	O
,	O
a	O
new	O
fast	O
travel	O
system	O
,	O
and	O
a	O
new	O
Stag	O
Station	O
to	O
discover	O
.	O
</s>
<s>
On	O
26	O
October	O
2017	O
,	O
the	O
second	O
DLC	B-Protocol
"	O
The	B-Device
Grimm	I-Device
Troupe	I-Device
"	O
was	O
released	O
,	O
adding	O
new	O
major	O
quests	O
,	O
new	O
boss	O
fights	O
,	O
new	O
charms	O
,	O
new	O
enemies	O
,	O
and	O
other	O
content	O
.	O
</s>
<s>
On	O
23	O
August	O
2018	O
,	O
the	O
final	O
DLC	B-Protocol
,	O
"	O
Godmaster	B-Device
"	O
was	O
released	O
,	O
containing	O
new	O
characters	O
,	O
boss	O
fights	O
,	O
music	O
,	O
a	O
new	O
game	O
mode	O
as	O
well	O
as	O
two	O
new	O
endings	O
.	O
</s>
<s>
Hollow	B-Device
Knights	I-Device
PC	O
and	O
PlayStation	B-Operating_System
4	I-Operating_System
versions	O
received	O
"	O
generally	O
favorable	O
"	O
reviews	O
and	O
the	O
Nintendo	B-Application
Switch	I-Application
version	O
received	O
"	O
universal	O
acclaim	O
"	O
,	O
according	O
to	O
review	B-Application
aggregator	I-Application
website	O
Metacritic	O
.	O
</s>
<s>
IGN	O
praised	O
Hollow	B-Device
Knights	I-Device
visuals	O
,	O
sound	O
,	O
music	O
,	O
and	O
"	O
a	O
million	O
other	O
details	O
"	O
in	O
building	O
atmosphere	O
.	O
</s>
<s>
On	O
IGN	O
,	O
Marks	O
stated	O
:	O
"	O
The	O
combat	O
in	O
Hollow	B-Device
Knight	I-Device
is	O
relatively	O
straightforward	O
,	O
but	O
starts	O
out	O
tricky	O
...	O
</s>
<s>
The	O
difficulty	O
of	O
Hollow	B-Device
Knight	I-Device
received	O
attention	O
from	O
reviewers	O
and	O
was	O
described	O
as	O
challenging	O
;	O
Vikki	O
Blake	O
of	O
Eurogamer	O
called	O
the	O
game	O
"	O
ruthlessly	O
tough	O
,	O
even	O
occasionally	O
unfair	O
"	O
.	O
</s>
<s>
Critics	O
also	O
made	O
comparisons	O
to	O
the	O
Dark	B-Application
Souls	I-Application
series	O
,	O
noting	O
the	O
mechanic	O
of	O
losing	O
currency	O
on	O
death	O
and	O
having	O
to	O
defeat	O
a	O
Shade	O
to	O
regain	O
it	O
.	O
</s>
<s>
Hollow	B-Device
Knight	I-Device
had	O
sold	O
over	O
500,000	O
copies	O
by	O
November	O
2017	O
and	O
surpassed	O
1,000,000	O
in	O
sales	O
on	O
PC	O
platforms	O
on	O
11	O
June	O
2018	O
,	O
one	O
day	O
before	O
releasing	O
on	O
Nintendo	B-Application
Switch	I-Application
,	O
where	O
it	O
had	O
sold	O
over	O
250,000	O
copies	O
in	O
the	O
two	O
weeks	O
after	O
its	O
launch	O
.	O
</s>
<s>
By	O
February	O
2019	O
,	O
Hollow	B-Device
Knight	I-Device
had	O
sold	O
over	O
2,800,000	O
copies	O
.	O
</s>
<s>
A	O
sequel	O
to	O
Hollow	B-Device
Knight	I-Device
titled	O
Hollow	B-Application
Knight	I-Application
:	I-Application
Silksong	I-Application
,	O
is	O
in	O
development	O
by	O
Team	B-Device
Cherry	I-Device
as	O
of	O
February	O
2019	O
,	O
and	O
is	O
set	O
to	O
be	O
released	O
on	O
Windows	O
,	O
Mac	O
,	O
Linux	B-Application
,	O
Nintendo	B-Application
Switch	I-Application
,	O
PlayStation	B-Operating_System
4	I-Operating_System
,	O
PlayStation	O
5	O
,	O
Xbox	B-Device
One	I-Device
,	O
and	O
Xbox	B-Device
Series	I-Device
X/S	I-Device
.	O
</s>
<s>
Team	B-Device
Cherry	I-Device
had	O
previously	O
planned	O
this	O
game	O
as	O
a	O
piece	O
of	O
downloadable	B-Protocol
content	I-Protocol
for	O
its	O
predecessor	O
,	O
but	O
decided	O
to	O
market	O
it	O
an	O
individual	O
title	O
as	O
its	O
content	O
grew	O
too	O
large	O
.	O
</s>
