Nintendo tumbler puzzle Nintendo tumbler puzzle The Nintendo tumbler puzzle, also known as the "Ten Billion Barrel" in English and originally in Japanese, is a mathematical puzzle in the style of Rubik's Cube. It was invented by Gunpei Yokoi of Nintendo in 1980 and was covered by (until the patent expired in March 1995 due to non-payment of a maintenance fee). It consists of a "cylinder" of transparent plastic divided into six levels, together with a black plastic "frame". The frame consists of upper and lower discs that are joined together through the middle of the cylinder. The top and bottom levels of
Rush Hour (puzzle) has a solution is PSPACE-complete. This is proved by reducing a graph game called Nondeterministic Constraint Logic, which is known to be PSPACE-complete, to generalized Rush Hour positions. Tromp and Cilibrasi (2004) showed that "Rush Hour" is still PSPACE-complete when the cars are of size 2 only. They also conjectured that "Rush Hour" is still nontrivial when the cars are of size 1 only. Rush Hour (puzzle) Rush Hour is a sliding block puzzle invented by Nob Yoshigahara in the 1970s. It was first sold in the United States in 1996. It is now being manufactured by ThinkFun (formerly Binary