Narbacular Drop

Narbacular Drop is an environmental puzzle video game developed by Nuclear Monkey Software. It was released for free online in 2005 for Microsoft Windows. It was the senior game project of students attending DigiPen Institute of Technology. The gameplay consists of navigating a dungeon using an innovative portal system. The player controls a pair of interconnected portals that can be placed on any non-metallic surface (wall, ceiling, or floor). Gabe Newell, managing director of Valve Corporation, took interest in the team's work and employed the whole staff at Valve. The developers went on to make Portal (2007) using many of the same concepts. The word Narbacular, which does not exist in any dictionary, was chosen primarily to aid in internet search engine results. Being mostly a proof of applied concept, the game contains only six puzzles to solve. However, members of the Narbacular Drop forum community have created a catalog of custom maps.

A princess, called No-Knees due to her inability to jump, was admired by her entire kingdom. A demon, imagining her kidnap would help in his quest to conquer the world, captures Princess No-Knees. He then locks her inside a cage in his mountain lair, under patrol of his minion, Impy. However, Wally, the spirit of the mountain, was mad at the Demon for creating his dungeon lair inside his home. He tells No-Knees he would assist her in escaping as long as she helped him to defeat the demon and allows her to use his power of portal creation.