Until recently, three Nintendo plastic puzzle games were known to exist: Challenge Dice from 1969, the familiar Ten Bilion from 1980 and the rare Crossover from 1981, seen here below left to right on the top row.
But now a fourth puzzle popped up, which predates the Challenge Dice and is even rare than Crossover. The game is called Fifteengame (フィフティーンゲーム).
Although an exact year of release is not known, given the style of Nintendo NG logo used it must be from the early to mid 1960s.
Unlike the other three Nintendo puzzles, which are all unique designs by Nintendo, Fifteengame is a well-known puzzle that already existed a long time before this Nintendo version was released.
The game is often referred to as Game of Fifteen or 15 puzzle. Fifteengame consists of 15 (you guessed it) numbered pieces and one extra piece.
The sixteenth piece contains the NG logo, which stands for 'Nintendo Game'. This piece is used to complete the puzzle when it's done, and prevent the pieces from sliding. But is does not play a role in the actual game.
The puzzle is started by sliding the pieces in random directions, so the numbers become scrambled.
After the numbers have been mixed, the object of the game then is to slide the pieces until the numbers are again neatly ordered in rows from low to high. It's not too difficult, even simple compared to Nintendo's other puzzles.
Although not so challenging to solve, it is very challenging to find. It is not included in any of the books on Nintendo's history, and it's existence was unknown for many years.
One recently sold on Yahoo Auctions in Japan for 38,277 yen (US$360). Not bad for some pieces of plastic!