Jigscore

"Attach on one side to score the number shown, attach on multiple sides to multiply the numbers" - This is the central rule that Jigscore is built around.
Missions alternate between needing a target score, and beating AI opponents. Rule variations and differing board layouts add to the variety.
The simple controls are easy to pick up. There are no time limits, play at the pace you want. The calculations are done for you. The game never tries to punish you. This is supposed to be fun! That doesn't mean it is easy.
Jigsaws and dominoes are the basis of the gameplay. Dots represent numbers, just as they do on dominoes and dice. A set of 60 pieces has one of each combination. This creates tactics based on knowing what has been played, and what is available, just like dominoes, cards, and many other traditional games. There are also tactics around trying to get three or four sided moves for much higher scores, but beware of creating opportunities for opponents in the games.
Pieces are allocated randomly (except during the three tutorial levels). There is no manipulation to affect difficulty, the level variations are sufficient for that.
Combinations for the tacticians:
The first set of pieces has the numbers 2 to 5. Each piece has four different numbers, or a number repeated on two adjacent sides plus two other numbers.
Later you will encounter a new set of pieces with the numbers 2 to 6. Each piece has four different numbers. As there are never repeated numbers, there is a "no blocking" rule that stops a number being repeated on multiple sides of an unused location.
Check out the Instructions ("?" on the level select screen) to see all the pieces together.