|JJ - Tobidase Daisakusen Part II|
|Japanese title||ジェイ ジェイ|
|Designer(s)||Hironobu Sakaguchi, Nobuo Uematsu, and Nasir Gebelli|
|Preceded by||3-D WorldRunner|
JJ (ジェイ ジェイ Jei Jei?) is an action game developed and published by Square for the Famicom in 1987. In English, it is sometimes referred to by its long form, Jumpin' Jack, or by its subtitle, Tobidase Daisakusen Part II. The game was only released in Japan.
The sequel to Tobidase Daisakusen (known in North America as 3-D WorldRunner), JJ is a typical scrolling shooter, but it incorporates a third-person view, where the camera angle is positioned behind the main character. As in the previous title, the main character Jack must travel through various worlds, armed with his laser cannon and jumping ability, to defeat the serpentbeasts who have overrun the planets.
JJ was the last game by Square to utilize the "3D mode" and 3D glasses, and was Square's last work before the inception of the popular Final Fantasy franchise. The soundtrack of JJ consists of eight tracks, and all of them are either remixed or reused from the game's prequel, 3-D WorldRunner. The game was scored by Nobuo Uematsu, and is Uematsu's 16th work of video game music composition.
Although the game was only released in Japan, it is entirely playable by non-Japanese speaking players. However, DvD Translations went ahead and released a translation patch which changes the title screen, and displays the ending text in English. The patch can be found here.
Although the two games were released only months apart, JJ showcased many graphical improvements over its predecessor 3-D WorldRunner. The sprites have been overhauled, while more attention was paid to small details; when fighting bosses in JJ, for example, Jack is shown with a jetpack. The world backdrops are also richer in detail.
Like 3-D WorldRunner, JJ supported a "3-D mode" where selecting the 3-D mode and wearing 3D glasses makes the game appear in three dimensions. The glasses used are different, however. It has been noted that "whereas the 3-D mode in 3-D WorldRunner only required red/blue 3D glasses, the 3-D mode in this game requires special 3-D glasses whose left and right lenses switch on and off for every scan of the TV to give a perfect 3-D effect. These glasses were released only in Japan as the Famicom 3D System. These glasses were similar in their operation to the Segascope glasses released for the Sega Master System.