<s>
Castle	B-Application
Adventure	I-Application
is	O
a	O
freeware	B-License
adventure	O
game	O
designed	O
by	O
Kevin	O
Bales	O
and	O
released	O
in	O
1984	B-Application
.	O
</s>
<s>
It	O
is	O
compiled	O
from	O
Microsoft	B-Language
BASIC	I-Language
.	O
</s>
<s>
Castle	B-Application
Adventure	I-Application
is	O
a	O
dungeon	O
crawl	O
with	O
little	O
backstory	O
.	O
</s>
<s>
The	O
player	O
interacts	O
with	O
the	O
environment	O
through	O
a	O
mix	O
of	O
keyboard	O
controls	O
and	O
a	O
text	B-Application
parser	I-Application
.	O
</s>
<s>
Fighting	O
in	O
Castle	B-Application
Adventure	I-Application
consists	O
of	O
directing	O
the	O
adventurer	O
into	O
a	O
monster	O
.	O
</s>
<s>
The	O
game	O
uses	O
the	O
text	B-Application
mode	I-Application
of	O
IBM	O
PC	O
compatibles	O
.	O
</s>
<s>
It	O
could	O
be	O
played	O
on	O
even	O
the	O
earliest	O
IBM	O
PC	O
display	O
equipment	O
,	O
such	O
as	O
the	O
IBM	B-Device
Monochrome	I-Device
Display	I-Device
Adapter	I-Device
and	O
the	O
IBM	B-Device
5151	I-Device
monitor	O
.	O
</s>
<s>
Home	O
of	O
the	O
Underdogs	O
called	O
the	O
game	O
"	O
One	O
of	O
the	O
most	O
memorable	O
ASCII	O
games	O
of	O
the	O
bygone	O
BBS	B-Application
era.	O
"	O
</s>
