ビックバイパー
is a Japanese-developed shoot 'em up video game published by Konami for the Sony PlayStation 2 video game console in 2004. "Gradius V" was largely developed under contract by Treasure, who had previously worked on "Radiant Silvergun" and "Ikaruga". The game is set predominantly in outer space where players control a fictional spacecraft called Vic Viper through a continuously scrolling background depicting the territories of Bacterian—an evil empire which serves as the player's enemy. "Gradius V" received overall positive reviews. Critics praised the level design, graphical design and "classic" revival, but criticized the game's difficulty.