<s>
Amnesia	B-Application
:	I-Application
The	I-Application
Dark	I-Application
Descent	I-Application
is	O
a	O
survival	O
horror	O
adventure	O
video	O
game	O
by	O
Frictional	O
Games	O
,	O
released	O
in	O
2010	O
for	O
Microsoft	B-Application
Windows	I-Application
,	O
Mac	B-Application
OS	I-Application
X	I-Application
and	O
Linux	B-Application
operating	I-Application
systems	I-Application
,	O
in	O
2016	O
for	O
the	B-Operating_System
PlayStation	I-Operating_System
4	I-Operating_System
platform	O
and	O
in	O
2018	O
for	O
the	B-Device
Xbox	I-Device
One	I-Device
.	O
</s>
<s>
The	O
game	O
features	O
a	O
protagonist	O
named	O
Daniel	O
exploring	O
a	O
dark	O
and	O
foreboding	O
castle	O
called	O
Brennenburg	B-Application
,	O
while	O
trying	O
to	O
maintain	O
his	O
sanity	B-Application
by	O
avoiding	O
monsters	O
and	O
unsettling	O
events	O
.	O
</s>
<s>
In	O
addition	O
,	O
the	O
game	O
's	O
soundtrack	O
is	O
available	O
for	O
purchase	O
and	O
a	O
free	O
content	O
expansion	O
Justine	B-Application
has	O
been	O
released	O
,	O
as	O
well	O
as	O
many	O
fan-made	O
expansions	O
and	O
stories	O
for	O
its	O
unique	O
"	O
Custom	O
Story	O
"	O
game	O
mode	O
.	O
</s>
<s>
An	O
indirect	O
sequel	O
to	O
The	B-Application
Dark	I-Application
Descent	I-Application
,	O
titled	O
Amnesia	B-Application
:	I-Application
A	I-Application
Machine	I-Application
for	I-Application
Pigs	I-Application
,	O
was	O
released	O
on	O
10	O
September	O
2013	O
.	O
</s>
<s>
The	O
Amnesia	B-Application
Collection	I-Application
–	O
which	O
contains	O
The	B-Application
Dark	I-Application
Descent	I-Application
,	O
its	O
Amnesia	B-Application
:	I-Application
Justine	I-Application
expansion	O
and	O
A	B-Application
Machine	I-Application
for	I-Application
Pigs	I-Application
was	O
released	O
for	O
PlayStation	B-Operating_System
4	I-Operating_System
on	O
22	O
November	O
2016	O
,	O
and	O
for	O
Xbox	B-Device
One	I-Device
on	O
28	O
September	O
2018	O
.	O
</s>
<s>
The	O
same	O
collection	O
was	O
released	O
on	O
the	O
Nintendo	B-Application
Switch	I-Application
on	O
12	O
September	O
2019	O
.	O
</s>
<s>
A	O
second	O
sequel	O
,	O
developed	O
by	O
Frictional	O
Games	O
,	O
Amnesia	B-Application
:	I-Application
Rebirth	I-Application
,	O
was	O
announced	O
on	O
6	O
March	O
2020	O
,	O
and	O
was	O
released	O
on	O
20	O
October	O
2020	O
.	O
</s>
<s>
Amnesia	B-Application
:	I-Application
The	I-Application
Dark	I-Application
Descent	I-Application
is	O
a	O
first-person	O
adventure	O
game	O
with	O
survival	O
horror	O
elements	O
.	O
</s>
<s>
The	O
player	O
takes	O
control	O
of	O
Daniel	O
,	O
who	O
must	O
navigate	O
Castle	O
Brennenburg	B-Application
while	O
avoiding	O
various	O
dangers	O
and	O
solving	O
puzzles	O
.	O
</s>
<s>
In	O
addition	O
to	O
a	O
health	O
indicator	O
,	O
Daniel	O
's	O
sanity	B-Application
must	O
be	O
managed	O
,	O
centered	O
around	O
an	O
"	O
afraid	O
of	O
darkness	O
"	O
mechanic	O
.	O
</s>
<s>
Sanity	B-Application
is	O
reduced	O
by	O
staying	O
in	O
the	O
dark	O
for	O
too	O
long	O
,	O
witnessing	O
unsettling	O
events	O
or	O
looking	O
directly	O
at	O
monsters	O
.	O
</s>
<s>
Low	O
sanity	B-Application
causes	O
visual	O
and	O
auditory	O
hallucinations	O
and	O
an	O
increased	O
chance	O
of	O
attracting	O
monsters	O
,	O
while	O
its	O
complete	O
depletion	O
results	O
in	O
a	O
temporary	O
drop	O
in	O
mobility	O
,	O
or	O
death	O
in	O
higher	O
difficulties	O
.	O
</s>
<s>
Light	O
sources	O
help	O
restore	O
sanity	B-Application
,	O
and	O
if	O
none	O
are	O
available	O
,	O
Daniel	O
may	O
use	O
tinderboxes	O
to	O
ignite	O
candles	O
and	O
torches	O
or	O
deploy	O
an	O
oil-burning	O
lantern	O
.	O
</s>
<s>
Hiding	O
in	O
dark	O
areas	O
where	O
monsters	O
will	O
not	O
notice	O
Daniel	O
is	O
also	O
effective	O
,	O
but	O
will	O
decrease	O
Daniel	O
's	O
sanity	B-Application
.	O
</s>
<s>
On	O
19	O
August	O
1839	O
,	O
a	O
young	O
man	O
awakens	O
in	O
the	O
dark	O
and	O
empty	O
halls	O
of	O
the	O
Prussian	O
Brennenburg	B-Application
Castle	O
with	O
no	O
memory	O
about	O
himself	O
or	O
his	O
past	O
.	O
</s>
<s>
The	O
note	O
instructs	O
Daniel	O
to	O
descend	O
into	O
the	O
Inner	O
Sanctum	O
of	O
the	O
castle	O
in	O
order	O
to	O
find	O
and	O
kill	O
its	O
baron	B-Application
,	O
Alexander	O
.	O
</s>
<s>
A	O
phonograph	O
in	O
the	O
cell	O
contains	O
a	O
recording	O
by	O
a	O
woman	O
named	O
Justine	B-Application
,	O
who	O
tells	O
the	O
unnamed	O
woman	O
that	O
she	O
is	O
the	O
subject	O
of	O
a	O
psychological	O
test	O
.	O
</s>
<s>
She	O
is	O
also	O
pursued	O
by	O
the	O
Suitors	O
,	O
three	O
monstrous	O
characters	O
who	O
turn	O
out	O
to	O
be	O
Justine	B-Application
's	O
former	O
paramours	O
,	O
now	O
twisted	O
by	O
physical	O
and	O
psychological	O
torture	O
.	O
</s>
<s>
The	O
woman	O
is	O
Justine	B-Application
,	O
who	O
staged	O
the	O
entire	O
experiment	O
to	O
see	O
if	O
she	O
still	O
had	O
any	O
compassion	O
for	O
humanity	O
within	O
herself	O
.	O
</s>
<s>
The	O
ending	O
sequence	O
's	O
dialogue	O
differs	O
depending	O
on	O
the	O
number	O
of	O
people	O
Justine	B-Application
had	O
rescued	O
.	O
</s>
<s>
Work	O
began	O
on	O
the	O
game	O
while	O
Penumbra	B-Application
:	I-Application
Requiem	I-Application
was	O
still	O
being	O
developed	O
,	O
with	O
the	O
company	O
working	O
on	O
both	O
projects	O
at	O
the	O
same	O
time	O
.	O
</s>
<s>
Initial	O
designs	O
of	O
the	O
game	O
varied	O
considerably	O
from	O
the	O
final	O
game	O
,	O
with	O
the	O
developers	O
interested	O
in	O
reintroducing	O
more	O
combat	O
elements	O
similar	O
to	O
those	O
utilized	O
in	O
their	O
first	O
commercial	O
title	O
Penumbra	B-Application
:	I-Application
Overture	I-Application
.	O
</s>
<s>
The	O
developers	O
soon	O
discovered	O
that	O
they	O
encountered	O
many	O
of	O
the	O
same	O
problems	O
and	O
difficulties	O
that	O
plagued	O
the	O
combat	O
in	O
that	O
game	O
however	O
,	O
and	O
the	O
design	O
was	O
further	O
changed	O
to	O
be	O
more	O
similar	O
to	O
the	O
style	O
set	O
out	O
by	O
Overtures	O
sequel	O
Penumbra	B-Application
:	I-Application
Black	I-Application
Plague	I-Application
.	O
</s>
<s>
This	O
was	O
done	O
due	O
to	O
the	O
success	O
of	O
Penumbra	B-Application
:	I-Application
Overture	I-Application
as	O
a	O
part	O
of	O
the	O
first	O
Humble	O
Indie	O
Bundle	O
.	O
</s>
<s>
The	O
extra	O
content	O
was	O
revealed	O
to	O
be	O
commentary	O
,	O
and	O
they	O
explained	O
in	O
the	O
comments	O
section	O
of	O
the	O
same	O
page	O
that	O
its	O
intended	O
function	O
was	O
similar	O
to	O
that	O
of	O
Valve	O
's	O
commentary	O
system	O
that	O
began	O
in	O
the	O
Half-Life	B-Application
2	I-Application
series	O
.	O
</s>
<s>
A	O
PlayStation	B-Operating_System
4	I-Operating_System
version	O
–	O
Amnesia	B-Application
Collection	I-Application
–	O
was	O
released	O
on	O
22	O
November	O
2016	O
via	O
PlayStation	B-Device
Network	I-Device
;	O
this	O
title	O
includes	O
The	B-Application
Dark	I-Application
Descent	I-Application
,	O
its	O
expansion	O
Amnesia	B-Application
:	I-Application
Justine	I-Application
,	O
and	O
the	O
sequel	O
Amnesia	B-Application
:	I-Application
A	I-Application
Machine	I-Application
for	I-Application
Pigs	I-Application
.	O
</s>
<s>
Just	O
two	O
days	O
after	O
its	O
release	O
on	O
PS4	B-Operating_System
,	O
Frictional	O
Games	O
posted	O
a	O
tweet	O
stating	O
that	O
the	O
port	O
managed	O
to	O
recoup	O
all	O
costs	O
and	O
"	O
more	O
"	O
.	O
</s>
<s>
On	O
23	O
September	O
2020	O
,	O
it	O
was	O
announced	O
that	O
Amnesia	B-Application
:	I-Application
The	I-Application
Dark	I-Application
Descent	I-Application
would	O
be	O
made	O
open	O
source	O
.	O
</s>
<s>
On	O
12	O
April	O
2011	O
,	O
Frictional	O
Games	O
released	O
an	O
extra	O
free	O
level	O
for	O
owners	O
of	O
the	O
Steam	B-Application
version	O
of	O
Amnesia	O
.	O
</s>
<s>
This	O
additional	O
campaign	O
is	O
set	O
apart	O
from	O
Brennenburg	B-Application
Castle	O
.	O
</s>
<s>
Justine	B-Application
was	O
released	O
on	O
Steam	B-Application
as	O
a	O
way	O
to	O
promote	O
the	O
then-upcoming	O
release	O
of	O
Portal	B-Application
2	I-Application
,	O
as	O
getting	O
100%	O
on	O
the	O
campaign	O
(	O
all	O
of	O
the	O
collectables	O
,	O
all	O
of	O
the	O
analysis	O
and	O
making	O
correct	O
choices	O
)	O
unlocks	O
a	O
message	O
from	O
the	O
fictional	O
company	O
Aperture	O
Science	O
.	O
</s>
<s>
Game	O
logic	O
can	O
be	O
implemented	O
using	O
the	O
AngelScript	B-Application
scripting	O
language	O
.	O
</s>
<s>
A	O
prominent	O
example	O
of	O
a	O
custom	O
story	O
is	O
Penumbra	B-Application
:	I-Application
Necrologue	I-Application
,	O
a	O
fan-made	O
sequel	O
to	O
Frictional	O
's	O
earlier	O
Penumbra	O
series	O
.	O
</s>
<s>
On	O
23	O
September	O
2020	O
,	O
Frictional	O
Games	O
announced	O
that	O
they	O
would	O
be	O
releasing	O
the	O
source	O
code	O
for	O
both	O
Amnesia	B-Application
:	I-Application
The	I-Application
Dark	I-Application
Descent	I-Application
and	O
Amnesia	B-Application
:	I-Application
A	I-Application
Machine	I-Application
For	I-Application
Pigs	I-Application
.	O
</s>
<s>
Both	O
games	O
are	O
available	O
as	O
open-source	B-Application
video	I-Application
games	I-Application
under	O
GNU	B-License
GPL-3.0-or-later	I-License
.	O
</s>
<s>
Amnesia	B-Application
:	I-Application
The	I-Application
Dark	I-Application
Descent	I-Application
has	O
received	O
very	O
positive	O
reviews	O
from	O
critics	O
,	O
with	O
consistent	O
praise	O
given	O
for	O
the	O
ominous	O
atmosphere	O
and	O
horror	O
elements	O
:	O
"	O
By	O
strongly	O
focusing	O
on	O
vision	O
and	O
hearing	O
,	O
the	O
distance	O
between	O
player	O
and	O
game	O
is	O
radically	O
diminished	O
.	O
</s>
<s>
They	O
also	O
released	O
details	O
about	O
how	O
much	O
money	O
each	O
platform	O
generated	O
for	O
them	O
by	O
analyzing	O
the	O
sales	O
from	O
their	O
online	O
store	O
,	O
with	O
70%	O
of	O
sales	O
coming	O
from	O
Windows	B-Application
users	O
and	O
15%	O
coming	O
from	O
users	O
of	O
Linux	B-Application
and	O
another	O
15%	O
coming	O
from	O
users	O
of	O
Mac	B-Application
OS	I-Application
X	I-Application
.	O
Frictional	O
did	O
however	O
note	O
that	O
their	O
store	O
was	O
the	O
only	O
place	O
anyone	O
could	O
purchase	O
the	O
Linux	B-Application
version	O
of	O
the	O
game	O
,	O
whereas	O
the	O
Mac	B-Application
OS	I-Application
X	I-Application
and	O
Windows	B-Application
versions	O
could	O
be	O
purchased	O
from	O
other	O
sources	O
,	O
meaning	O
that	O
the	O
total	O
percentage	O
of	O
Linux	B-Application
sales	O
is	O
actually	O
considerably	O
smaller	O
compared	O
to	O
other	O
platforms	O
taken	O
collectively	O
.	O
</s>
<s>
Observing	O
that	O
their	O
own	O
Mac	B-Application
OS	I-Application
X	I-Application
sales	O
did	O
not	O
go	O
down	O
from	O
their	O
own	O
store	O
even	O
as	O
services	O
like	O
Steam	B-Application
picked	O
up	O
the	O
game	O
for	O
that	O
platform	O
,	O
meaning	O
that	O
it	O
did	O
not	O
steal	O
customers	O
from	O
their	O
store	O
but	O
instead	O
opened	O
up	O
a	O
new	O
market	O
,	O
they	O
decided	O
this	O
makes	O
a	O
good	O
incentive	O
for	O
other	O
stores	O
to	O
support	O
Linux	B-Application
as	O
well	O
.	O
</s>
<s>
In	O
2015	O
,	O
Kotaku	O
originally	O
ranked	O
Amnesia	O
as	O
the	O
2nd	O
best	O
horror	O
game	O
of	O
all	O
time	O
,	O
beaten	O
only	O
by	O
P.T.	B-Application
,	O
but	O
moved	O
it	O
to	O
1st	O
after	O
P.T.	B-Application
</s>
<s>
An	O
indirect	O
sequel	O
called	O
Amnesia	B-Application
:	I-Application
A	I-Application
Machine	I-Application
for	I-Application
Pigs	I-Application
was	O
released	O
on	O
10	O
September	O
2013	O
,	O
developed	O
by	O
The	O
Chinese	O
Room	O
and	O
published	O
by	O
Frictional	O
Games	O
.	O
</s>
<s>
A	B-Application
Machine	I-Application
for	I-Application
Pigs	I-Application
is	O
an	O
indirect	O
sequel	O
to	O
The	B-Application
Dark	I-Application
Descent	I-Application
which	O
,	O
while	O
set	O
in	O
the	O
same	O
universe	O
,	O
takes	O
place	O
in	O
an	O
alternative	O
history	O
with	O
different	O
characters	O
.	O
</s>
<s>
The	O
third	O
game	O
in	O
the	O
series	O
,	O
titled	O
Amnesia	B-Application
:	I-Application
Rebirth	I-Application
was	O
announced	O
on	O
6	O
March	O
2020	O
.	O
</s>
<s>
The	O
game	O
was	O
released	O
on	O
20	O
October	O
2020	O
for	O
PlayStation	B-Operating_System
4	I-Operating_System
,	O
Linux	B-Application
and	O
Windows	B-Application
.	O
</s>
