Tokyo Beat Down, or Yajuu Deka (野獣刑事 東京同時多発テロを鎮圧せよ!, lit. Beast Cops: Suppress frequently occurred terroism in Tokyo) in Japan, is a 2008 side-scrolling beat-em-up released for the Nintendo DS. It is being published by Atlus (North America) and developed by Tamsoft.
The story takes place in Yaesu, home of the so-called "Beast Cops". As the name implies, these Beast Cops have extreme methods of taking criminals down in Tokyo.
Tokyo Beat Down was released in Japan on September 18, 2008 and in North America on March 31, 2009
Source: Wikipedia, "Tokyo Beat Down", available under the CC-BY-SA License.