<s>
The	B-Application
Trap	I-Application
Door	I-Application
is	O
a	O
video	O
game	O
published	O
for	O
the	O
ZX	B-Operating_System
Spectrum	I-Operating_System
in	O
1986	B-Application
by	O
Piranha	O
Software	O
and	O
ported	O
to	O
the	O
Amstrad	B-Device
CPC	I-Device
and	O
Commodore	O
64	O
by	O
Five	O
Ways	O
Software	O
.	O
</s>
<s>
It	O
was	O
written	O
by	O
Don	O
Priestley	O
and	O
based	O
on	O
the	O
British	O
children	O
's	O
television	B-Application
show	I-Application
of	I-Application
the	I-Application
same	I-Application
name	I-Application
.	O
</s>
<s>
In	O
order	O
to	O
help	O
him	O
complete	O
his	O
task	O
,	O
Berk	O
must	O
make	O
use	O
of	O
the	O
many	O
objects	O
lying	O
around	O
his	O
part	O
of	O
the	O
castle	O
as	O
well	O
as	O
the	O
creatures	O
that	O
emerge	O
from	O
the	B-Application
trap	I-Application
door	I-Application
.	O
</s>
<s>
Berk	O
will	O
also	O
need	O
help	O
from	O
some	O
of	O
the	O
strange	O
creatures	O
that	O
lurk	O
in	O
the	O
caverns	O
under	O
the	B-Application
trap	I-Application
door	I-Application
and	O
these	O
creatures	O
can	O
often	O
be	O
as	O
much	O
a	O
hindrance	O
as	O
a	O
help	O
(	O
as	O
well	O
as	O
downright	O
dangerous	O
)	O
.	O
</s>
<s>
Once	O
Berk	O
has	O
finished	O
taking	O
advantage	O
of	O
a	O
creature	O
's	O
"	O
assistance	O
"	O
he	O
also	O
has	O
to	O
find	O
a	O
way	O
of	O
making	O
sure	O
it	O
goes	O
back	O
down	O
the	B-Application
trap	I-Application
door	I-Application
.	O
</s>
<s>
Once	O
all	O
four	O
meals	O
have	O
been	O
delivered	O
on	O
time	O
,	O
Berk	O
must	O
clean	O
up	O
the	O
castle	O
by	O
shoving	O
every	O
monster	O
-	O
including	O
Boni	O
and	O
Drutt	O
-	O
down	O
the	B-Application
Trap	I-Application
Door	I-Application
;	O
if	O
the	O
game	O
is	O
in	O
"	O
Super	O
Berk	O
"	O
mode	O
,	O
The	O
Thing	O
will	O
then	O
send	O
down	O
a	O
safe	O
as	O
a	O
reward	O
,	O
which	O
Berk	O
must	O
crack	O
open	O
to	O
complete	O
the	O
game	O
successfully	O
.	O
</s>
<s>
To	O
promote	O
the	O
release	O
of	O
The	B-Application
Trap	I-Application
Door	I-Application
,	O
Piranha	O
Software	O
partnered	O
with	O
Computer	O
Gamer	O
magazine	O
to	O
run	O
a	O
contest	O
wherein	O
readers	O
submitted	O
recipes	O
for	O
the	O
Thing	O
Upstairs	O
,	O
and	O
25	O
winning	O
entrants	O
received	O
a	O
copy	O
of	O
the	O
game	O
.	O
</s>
<s>
The	B-Application
Trap	I-Application
Door	I-Application
was	O
followed	O
by	O
a	O
sequel	O
in	O
1987	O
called	O
Through	O
The	B-Application
Trap	I-Application
Door	I-Application
,	O
also	O
written	O
by	O
Priestley	O
and	O
published	O
by	O
Piranha	O
.	O
</s>
