This ingenious set of 48 graded 3D challenges requires you to use logical deduction combined with maths to correctly position up to five colour-coded ice cubes in a tower. To solve each puzzle, the numbers on the outer face of each side of the ice cubes must vertically add up to the totals shown at the foot of each of the four sides of the tower... all at the same time. It’s straightforward enough until you start tackling puzzles without knowing which ice cubes you need to use.

This brand new set of puzzles will slowly drive you mad with sub-zero frustration, but each time you succeed, you’ll want to push yourself that bit further! The concept is so clever and the puzzles  incredibly addictive. Wonderful.