If there's one sentence guaranteed to chill PC Advisor's blood, it is surely this one: "It's just like a crossword – but with numbers!"
We can probably assume, however, that those still reading are able to stomach Su Doku and its ilk. So you may be pleased to hear that there's a new kid on the block, and it's called Ka Kuro. Isn't it always the way; you wait ages for an eastern arithmetical puzzle phenomenon, then two come along at once.
Ka Kuro's principle is similar to that of its more famous rival – you place digits into a grid using logic and deduction, avoiding repetitions within continuous lines. There's an additional element, so to speak – numbers above or to the left of each row or column indicate the sum it should produce – and the grid is slightly more complex than the one used in Su Doku. We also felt a larger element of trial and error was required, which took away some of the satisfaction of reaching an elegant solution.
Greenstreet's electronic interpretation of the game, as tends to be the case with products of this nature, adds little to the mix except sheer volume – it can generate grids until the cows come home – although the ability to add 'pencil' annotations can be mildly useful when following a speculative flight of fancy. Of course, if you like kicking it old-school, you can always print the thing out. In what is presumably a move to compete with the Minesweepers of this world, Greenstreet has included an amusing Boss Key to hide the puzzle when authority figures get near your monitor. Of course, we had no use for this function, but it shows laudable attention to detail.