Think it's not just adjacent but diagonals too; got a 16 to do, put 4 up down and on the sides and it doesn't show green.
HOW TO PLAY
STEP 1: CHOOSE A NUMBER
There will be four numbers below the board from which you can choose. Choose one and continue to step 2.
STEP 2: CHOOSE AN EMPTY TILE FROM THE BOARD
You have chosen a number and now it is time to use it. Pick an empty tile from the board. When a tile is chosen that tile and those at the same row and column take the value of the number that you have chosen. If a tile already has a value from another picked tile then the two values are added. Keep going until there are no empty tiles.
STEP 3 COMPLETE ALL THE OBJECTIVES
The board will also have objectives. The red tiles on the board are the objectives. Every objective has a number and in order to complete it the sum
of its adjacent tiles(up, down, left, right) must be equal with the number of the objective. When an objective is completed will become green. Fulfill all the objectives to clear the board.
Think it's not just adjacent but diagonals too; got a 16 to do, put 4 up down and on the sides and it doesn't show green.