This puzzle has been constructed for the German puzzle grand prix round this year. Unfortunately, it was too difficult to be used in that round.
Rules (taken from the grand prix instruction booklet): Draw a single, non-intersecting loop that only consists
of line segments between the dots along the dashed
lines. A number inside a cell indicates how many of the
edges of that cell are part of the loop.
The puzzles lives on a six-sided cube, which is shown as a cube net.
Solution code: On the cube net, row 8 and column 8: The lengths of the continuous segments between vertical/horizontal border (i.e. the sum of the segments should be 15/20)