Jazz Jackrabbit 3 (alternatively called Jazz Jackrabbit 3D: Adventures of a Mean Green Hare) is the cancelled game of the series. Spearheaded by Dean "Noogy" Dodrill (an animator for Jazz Jackrabbit 2) and coded by World Tree Games, it was being developed for the original Unreal Engine technology in 1999. As the game's alternate name implies, Jazz would have ventured into the realm of 3D for the first time. The game was planned for release on PC and PlayStation 2.Development of the game was ceased part way through in May 2000 as Epic MegaGames was unable to find a publisher. Since then, the alpha has been leaked on to the internet. Besides Jazz, other characters such as Spaz and Lori were intended to be playable, but in the alpha, only Jazz is playable.
Following the events of Jazz Jackrabbit 2, Jazz Jackrabbit and his wife, Eva Earlong, settle down in Carrotus Castle and become parents. Devan Shell, the main antagonist of the series, kidnaps their children, taking them into an alternate universe via the time machine from the previous game.
Jazz Jackrabbit 3 is a third-person shooter with platforming and adventure game elements. The mouse is used to aim and shoot, while the keyboard moves Jazz around the world. Jazz can fire his weapon, or charge up a more powerful shot. Jazz's arsenal can be expanded using coins collected to purchase new weapons and combine them with Elemental "Dream Cells" to create various weapon effects. In the alpha, only Fire and Ice Dream Cells can be acquired, and usable with two guns (the standard Blaster and the Gizmo Gun). When Jazz moves around in a level, he leaves a trail of footprints on the ground.
Unlike the previous installments, Jazz Jackrabbit 3 has no levels. Rather, it is divided into sections, similar to Super Metroid. At specific points in a map, the player can travel back and forth between these sections. Each new area that is visited is prefaced by its name.
Source: Wikipedia, "Jazz Jackrabbit", available under the CC-BY-SA License.