Enigma

Enigma is another logical, picture-forming Conceptis puzzle. According to Conceptis, the puzzle was developed originally in Japan and first published by Byakuya Shobo under the name Number Net.

There are colour and mono versions, although generally speaking, the mono versions make for better puzzles. A peculiarity of the puzzle is that in the early stages, it doesn't present much of a challenge: the 1s and 2s can be completed without any problems, and the puzzle doesn't present much in the way of difficulty until the bigger numbers are reached.

Related puzzles:

Instructions:

Reveal a hidden picture by shading certain squares. Apart from the 1s (which can be filled in immediately), each number is half of a pair. Join pairs of numbers so that the number of cells in a linking path (including the cells containing the numbers) is exactly the same as the numbers being paired. Paths may not cross one another. Once all paths have been completed, cells with paths can be shaded in to reveal a picture.