"batankyu" is an onomatopea in a two players tetris-like game named
Puyo Puyo Tsu. "batankyu" mimicks the sound of stacked objects collapsing,
the equivalent of "badaboum" and "patatra" in french.
In Puyo Puyo Tsu, a player loses when the third column of his pit is completely
filled with coloured blobs called puyos that are stacked on each other.
The stack then collapses and the avatar of the player shouts "batankyuuuuuuuuuuu".
I'm completely addicted to this game...
http://www.youtube.com/results?search_query=puyo%20puyo%20tsu