The program options window is reached by pressing F3
On top there's the section Options for new games : it lets you specify what options the new games will have when they are started for first time (once a new game is started these options can be changed in the Game Info & Options window).
Next, under Program options:
Show ToolTips : If you leave the mouse a moment over a button or option, the program displays a box explaining that object.
Hide action bar : To hide the bar at the bottom of the screen (the buttons on that bar are all in the menu so hiding it will leave more free space on the screen).
Solution frame centered : The frame where to put the solved pieces will be centered on the screen rather than on the top/right corner.
Anchor pieces : The pieces, when placed in their position in the solution frame, will be anchored to the background. To move an anchored piece you have to double click it.
Hide closed trays if empty : This will hide the minimized (closed) trays if they contain no pieces (the idea is that empty trays don't use screen space, but if tray contains pieces you don't miss it). Anyway hidden trays are still working, and you can activate them with the keyboard. Unchecking that option will show them.
Ghost image transparency : To set the level of transparency of the ghost image (you must set the Ghost image in the " This game " tab).
Full Screen : To switch between Full screen mode (the program uses the whole screen) or Windowed mode (the program runs in a regular window showing the Start Menu at the bottom and other possible elements depending on your settings).
At startup resume last game : If you leave the program with a puzzle in progress (not completed) the next time you start it will load that game in progress as it was when you left it. With that option unchecked, at startup, the program will display the gallery from where you can either resume this game or play other puzzles.
Click+Release for dragging This control de behavior of the mouse when you click and release the mouse on a piece. The default option is Depends but you may prefer any, just choose the one most comfortable for you:
Connecting pieces: When a piece connects to others the program produces visual effects. You can disable them partially or completely.
On completed puzzles: : When you exit a puzzle in progress the program saves it automatically. If you exit a completed puzzle the program will also save the completed game but you might want not to store these. Checking Ask if erase the program will ask what to do about saving that completed game.
Frame completed puzzles : When a puzzle is completed, the program will display a colored frame around the puzzle.
Hide outlines when completed : The program will remove the outline of the pieces when it is completed (this happens only on puzzles created with your own images).
Piece borders: : Controls the thickness of the contour of the pieces. Choose Sharp or Thin if you usually work puzzles of many pieces (when the pieces are small). Bold has a cartoonish effect, good with large pieces (good for kids)
Block public score: : When you work a puzzle the program can calculate a score based on your performance. The score is sent to our server (anonymously) to build a ranking of best players of a puzzle. This options blocks sending this data to our server. (The option is disabled if you checked Don't connect to cloud server or Show score set to Never as in these cases there's no score sent anyway)
You can also customize the sounds of the program, choose tab Sounds at the top. More info about this here...............
Additionally there are some Advanced options, you can reach them by pressing Ctrl+F3 in the program (the options are self-explained with the tooltips).