<s>
Sudden	B-Protocol
Attack	I-Protocol
2	I-Protocol
(	O
Korean	B-Operating_System
:	O
서든어택	O
2	O
)	O
was	O
a	O
free-to-play	O
multiplayer	O
first-person	O
shooter	O
online	O
game	O
developed	O
by	O
the	O
South	O
Korean	B-Operating_System
company	O
GameHi	O
(	O
Nexon	O
GT	O
)	O
.	O
</s>
<s>
It	O
is	O
a	O
sequel	O
to	O
the	O
original	O
Sudden	B-Application
Attack	I-Application
.	O
</s>
