Puzzle filtering :

In the the Free editions the puzzle filter has been taken out. There are 10 puzzles only per polyhedron.

Since puzzles have no fixed sorting order (see Mathematics & difficulty rating) or can't even be clearly categorised, the tool that will help you find a puzzle that suits your interest is the 'Puzzle Filter'.

• All Puzzles use triangles & rotators.
• The triangles have colors, facemarkers and directions. (see Game Basics if you're not clear on this)
• The rotators use a rotationtype. There can be more than one in a puzzle.
• Both spots usually taken by a triangle or rotator can be left empty. These are called 'Holes'.

Filtering options can be switched on or ignored / switched off. When you switch them on, (the background is green) the filter is applied. 

Triangles in use are distinguished by  :

• Number of different Colors
• Faces
• Directions

Number of colors : I.e. 'How many colors are used in the puzzle ?'. There is an extra option of 'Holes', which means that there are empty spots in use.
It may be noted that holes cannot have faces or directions, but can be moved around by everything else being actually moved. (Imagine 'holes' in semiconductors - hence the name).

Faces : 
The 'face' is the up / down side of each triangle. Without facemarkers they are indistinguishable. To distinguish between them, a colored circle (dot, smartie, ..) in the center if the triangle is added. Obviously the colors have to be different :).
The filter options are All, Some, Any & None.

• All' & 'None' are pretty self explanatory.
• 'Some' means that simply not all triangles have facemarkers, but well, ... at least 'Some' do.. 
• 'Any' stands for facemarkers being generally there, but it can be anythings between 1 and All. (logically speaking it's All or Some).

Directions :  Exactly the same system as in 'Faces' above. 
In the image, the filter is set to no faces & no directions.

Rotations used in a puzzle are distinguished by :

• Amount / Nr. of Rotationtypes goes from 1 to 3, or then 4 or more.
  I.e. How many different rotationtypes in a puzzle.
  
• Include Rotationtype : marking a specific type, the filter will only show those puzzles where those rotations are used. If you allow for 'Holes', then there may be empty spots around which you have to solve the patterns.

The 'Randomized' filter distinguishes between just that, and the opposite. Randomized puzzles have no ending pattern, so they need to be shuffled, and played back to the bstart-pattern. The Base and Free Edition Puzzles are all non-randomized. that is 'directional' puzzles.

The other two filters just exclude / include puzzles you already may have solved or where you have saved your progress.

The button for every puzzle contains markers showing if the puzzle has a savegame and your skill and genius -points earned on it, once it has been solved.

Future filter suggestions are welcome. A future (planned) update shall also include sorting options ! The need for sorting will arise with more and more puzzles being created.