<s>
Gravity	B-Application
Force	I-Application
is	O
a	O
video	O
game	O
series	O
for	O
the	O
Amiga	B-Device
.	O
</s>
<s>
The	O
first	O
game	O
in	O
the	O
series	O
was	O
published	O
commercially	O
by	O
Kingsoft	O
GmbH	O
in	O
1989	O
,	O
as	O
a	O
Thrust-clone	O
.	O
</s>
<s>
In	O
1994	O
,	O
fans	O
Jens	O
Andersson	O
and	O
Jan	O
Kronquist	O
obtained	O
permission	O
from	O
creator	O
Stephen	O
Wenzler	O
at	O
Kingsoft	O
to	O
release	O
a	O
sequel	O
,	O
Gravity	B-Application
Force	I-Application
2	I-Application
.	O
</s>
<s>
They	O
collaborated	O
on	O
the	O
graphics	O
with	O
Christer	O
Masmanidis	O
,	O
Niklas	O
Ivarsson	O
,	O
and	O
Jan	O
Warner	O
(	O
of	O
Amiga	B-Device
demoscene	O
group	O
Nexus	O
)	O
.	O
</s>
<s>
The	O
game	O
was	O
re-distributed	O
to	O
the	O
BBS	O
,	O
and	O
at	O
this	O
point	O
the	O
creators	O
published	O
an	O
update	O
making	O
the	O
game	O
shareware	B-License
.	O
</s>
<s>
As	O
a	O
complete	O
rewrite	O
,	O
sharing	O
no	O
code	O
with	O
the	O
Kingsoft	O
original	O
,	O
Gravity	B-Application
Force	I-Application
2	I-Application
added	O
destroyable	O
walls	O
,	O
single	O
player	O
missions	O
and	O
a	O
2-player	O
multiplayer	O
mode	O
,	O
both	O
split-screen	O
and	O
over	O
a	O
null	O
modem	O
cable	O
.	O
</s>
<s>
In	O
1994	O
,	O
Gravity	B-Application
Force	I-Application
2	I-Application
attracted	O
the	O
attention	O
of	O
British	O
computer	O
game	O
magazine	O
Amiga	B-Device
Power	O
,	O
who	O
released	O
it	O
on	O
the	O
coverdisk	O
of	O
issue	O
39	O
,	O
and	O
the	O
following	O
year	O
ranked	O
it	O
the	O
second	O
best	O
Amiga	B-Device
game	O
of	O
all	O
time	O
(	O
behind	O
Sensible	B-Application
Soccer	I-Application
)	O
.	O
</s>
<s>
Their	O
endorsement	O
continued	O
in	O
1995	O
through	O
the	O
commissioning	O
of	O
Gravity	B-Application
Power	I-Application
,	O
a	O
slightly	O
enhanced	O
version	O
which	O
was	O
published	O
on	O
the	O
coverdisk	O
of	O
issue	O
50	O
.	O
</s>
<s>
Amiga	B-Device
Power	O
had	O
asked	O
for	O
a	O
4-player	O
mode	O
,	O
but	O
this	O
did	O
not	O
make	O
it	O
into	O
the	O
final	O
version	O
as	O
it	O
would	O
have	O
required	O
substantial	O
rework	O
to	O
the	O
codebase	O
.	O
</s>
<s>
The	O
original	O
Gravity	B-Application
Force	I-Application
was	O
reviewed	O
in	O
1989	O
by	O
German	O
game	O
magazine	O
ASM	O
,	O
receiving	O
75/100	O
points	O
,	O
and	O
by	O
Power	O
Play	O
in	O
the	O
same	O
year	O
,	O
receiving	O
72/100	O
.	O
</s>
<s>
In	O
1995	O
,	O
Amiga	B-Device
Format	O
praised	O
Gravity	B-Application
Force	I-Application
2	I-Application
,	O
identifying	O
the	O
non-commercial	O
nature	O
of	O
the	O
game	O
as	O
a	O
critical	O
factor	O
in	O
its	O
success	O
:	O
"	O
The	O
programmers	O
did	O
n't	O
have	O
to	O
succumb	O
to	O
the	O
creative	O
restraints	O
of	O
anxious	O
publishers	O
and	O
deadlines	O
.	O
</s>
<s>
In	O
2011	O
,	O
Gravity	B-Application
Power	I-Application
was	O
named	O
one	O
of	O
the	O
1001	O
Video	O
Games	O
You	O
Must	O
Play	O
Before	O
You	O
Die	O
.	O
</s>
<s>
In	O
2016	O
,	O
the	O
book	O
Swedish	O
video	O
game	O
development	O
from	O
the	O
50s	O
to	O
the	O
90s	O
was	O
published	O
,	O
featuring	O
an	O
interview	O
with	O
Andersson	O
and	O
Kronquist	O
,	O
and	O
in	O
2017	O
another	O
interview	O
featured	O
in	O
the	O
book	O
Generation	O
500	O
,	O
in	O
which	O
the	O
game	O
was	O
described	O
as	O
"	O
one	O
of	O
the	O
Amiga	B-Device
platform	I-Device
's	O
most	O
loved	O
titles	O
"	O
.	O
</s>
<s>
A	O
planned	O
sequel	O
to	O
Gravity	B-Application
Force	I-Application
2	I-Application
,	O
to	O
be	O
called	O
gf2k	O
was	O
abandoned	O
at	O
an	O
early	O
stage	O
in	O
2001	O
.	O
</s>
<s>
The	O
developers	O
did	O
eventually	O
release	O
a	O
multi-platform	O
sequel	O
in	O
2015	O
named	O
Gravity	B-Application
Force	I-Application
20	O
,	O
built	O
using	O
the	O
Unity	B-Application
engine	I-Application
.	O
</s>
<s>
On	O
September	O
21	O
,	O
2008	O
the	O
developers	O
of	O
Gravity	B-Application
Force	I-Application
2	I-Application
released	O
the	O
Amiga	B-Device
Motorola	B-Device
680x0	I-Device
assembly	B-Language
language	I-Language
source	O
code	O
for	O
"	O
nostalgic	O
interest	O
"	O
without	O
specified	O
license	B-License
.	O
</s>
<s>
In	O
April	O
2017	O
the	O
authors	O
clarified	O
the	O
game	O
and	O
source	O
code	O
license	B-License
as	O
CC	O
BY-SA	O
4.0	O
.	O
</s>
<s>
Many	O
similarly	O
titled	O
clones	B-General_Concept
have	O
since	O
appeared	O
.	O
</s>
<s>
These	O
games	O
are	O
generally	O
freeware	O
and	O
position	O
themselves	O
as	O
direct	O
descendants	O
of	O
Gravity	B-Application
Force	I-Application
and	O
Gravity	B-Application
Power	I-Application
rather	O
than	O
Thrust	B-Application
.	O
</s>
