There are often only 2 or 3 triangles, squares or rectangles (in later levels and more) trains must be brought into the appropriate form with 2, 3 or 4. Looks totally out of simple, one can also bring in a very short time to despair. Play an important role and the different colors of the shapes. For a contiguous areas of the same color can be moved in one piece (or train), on the other hand you can by skillfully overlapping shapes (which immediately their color changes) suitable rest areas separating them. All this is more difficult to describe with words than it actually is and is very clearly explained in the first few levels, which tend to be regarded as a tutorial.
Zengrams is a typical game where I asked myself again and again at the end of many level, why I did not come quickly to the solution which was mostly yet so obvious, at least in the first half of the game. From about level 30 (out of 70) the difficulty then increases significantly, without it but is too complex or even unsolvable.
A minimalist, very motivating puzzler with high game and a lot of times the wow factor. I love those games where you have to expend a bit of patience and activate his brain time off the beaten paths of thought.
Tested + works just fine on a Galaxy Tab S.
Full 5 stars!