Puzzle games like Sudoku — and where Ekkon differs
If you like Sudoku, it is usually for one reason: the answer is already there, and you can reason your way to it without guessing. Here are some relatives, and what each does differently.
What Sudoku actually gives you
A Sudoku board is 9×9. Every number from 1 to 9 appears once in each row, each column and each 3×3 box. Some numbers are given at the start, and the rest follows from the rules. The skill is spotting which square has the fewest options left, and working out from there.
Killer Sudoku
The same board, but the given numbers are replaced by outlined cages with a sum. No number repeats inside a cage. You do as much arithmetic as deduction.
Kakuro
A crossword made of numbers. Every run has a total it must hit, and no digit repeats within a run. Good if you like arithmetic and logic pulling together.
Nonogram (Picross)
The numbers along the edges tell you how long the filled runs are. Solve it correctly and a picture appears. More spatial than numerical.
Futoshiki
The closest classic to Ekkon. Every number from 1 to the board size appears once in each row and column, and between some neighbouring squares sits a greater-than or less-than sign. You reason from comparisons rather than from sums.
Ekkon
Ekkon shares its skeleton with Sudoku and Futoshiki: every number from 1 to the board size, once in each row and column. Two things are different.
The board is completely empty. Nothing is given, and no comparisons are printed on the board.
And information costs. You send an echo at a square, and the square tells you how many of its neighbours are higher than itself — never its own number. Every echo counts against your score, which is measured against par, the way golf does it.
That moves the skill somewhere else. In Sudoku you hunt for the square with the fewest options. In Ekkon you hunt for the echo that says the most — and a square in the middle, with four neighbours, says far more than a corner with two.
Which suits whom
If you want a board to sink into and finish, Sudoku and Kakuro are built for that. If you want something shorter, where every move costs and you have to choose where to spend it, Ekkon is closer. It takes a couple of minutes, everyone gets the same board each day, and you can compare how you did.
Ekkon is free, needs no sign-up, and comes in English and Norwegian.