Narbacular Drop

Narbacular Drop is a 2005 puzzle-platform game developed by Nuclear Monkey Software. 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 two interconnected portals that can be placed on any non-metallic surface (wall, ceiling, or floor). Gabe Newell, managing director of Valve, took interest in the team's work and employed the whole staff at Valve. The developers went on to develop the critically acclaimed Portal 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.