There's certainly no shortage of number puzzles lurking around the dark, damp corners of the eShop. Sudoku is a prime culprit, and we wouldn't be at all surprised if there was a degree of puzzle overlap between them all, however mathematically unlikely that may be.
Kakuro, on the other hand, is much less of a bruised dead horse — with only one other eShop presence, one might say it's not even been thwacked yet. With a similar approach to numerical diversity as sudoku and the presentation of a crossword puzzle, each "word" is a number that you must add up to using the numbers 1-9. For example, if you have three boxes to add up to 12, you can't spam the boxes with 4-4-4. Instead, you'll have to use a combination that doesn't include duplicates in the sequence, like 2-4-6. As in sudoku, you can't use numbers that are already in use on intersecting lines, and it all has to add up everywhere and oh god the math.
This being a different type of puzzle than sudoku, HAMSTER has included a few niceties to make your kakuro playing a touch easier. One handy shortcut allows you to tap the "question" number — i.e. the one that you have to add up to — to see which numbers actually add up to make the answer, listed in numerical order rather than sequential so as not to solve the puzzle for you. A menu tucked in the pause menu also lists all possible combinations for certain numbers to help you feel less overwhelmed when anything over 10 appears on the grid.
And that's about it, really. The "check" option is still rather useless as it doesn't actually let you know whether something is wrong, leading to a lot of messed-up backtracking that can just about kill any momentum you had if something goes horribly wrong late in the puzzle. You can save your puzzle progress but only for one at a time. It's about as vanilla a puzzle experience as can be, and 50 puzzles for $4.99 doesn't seem like that much of a bargain.
Kakuro by Nikoli is straightforward almost to a fault, and value-neutral novelties like local multiplayer make it difficult to justify its asking price. Considering there is only one other kakuro title on the eShop — the rather excellent and more diverse Telegraph Sudoku & Kakuro — Kakuro by Nikoli is by default a decent next step for more of this type of puzzle. However, if this is your first kakuro rodeo then you're better off grabbing Telegraph's less expensive and more expansive offering.