Instant Insanity II consists of 4 linear columns and 4 circular rows of colored tiles on
a cylinder. Above the 4 rows of tiles, at the top of the cylinder, there is an extra row,
which we call the top ring, with two adjacent empty slots. The bottom row of the cylinder
and the top ring, with its two slots for tiles, rotate. Each tile may slide up or down its
column, alone or with other tiles of the column, if the column contains an empty slot. The
16 tiles are of ve colors: four blue tiles, and three each of red, green, yellow, and white
tiles. Instant Insanity II's classic challenge is to congure the tiles so that each row and
column contains four dierent colors. The ultimate challenge involves a further aspect of
the puzzle. Following a circular path around each row, each tile has, at each juncture, a
small semicircular halfmoon" of color. Positioned with the top ring on top, the halfmoon
on the right of each tile has the same color as the tile, while the left halfmoon has a dierent
color. Among the tiles of a given color, the nonmatching halfmoons have distinct colors.
The ultimate challenge is to nd a classical solution in which the pair of semicircles at the
junctures match.
The Instant Insanity