For Kakuro solvers, week oneWhat games are like Kakuro?
The games most like Kakuro keep its core rule, that every move is checked against a target sum, and change what you move: Killer Sudoku adds sum cages to sudoku, and Sumbriska replaces the grid with islands you balance by flipping bridges. We make Sumbriska, so this page is our first-week guide for people arriving from Kakuro, also known as Cross Sums. The board above is the whole rule in miniature. Updated November 2026.
Other sum puzzles worth knowing: Killer Sudoku (sudoku with cage totals, good if you like Kakuro's combination tables) and KenKen-style cage puzzles (targets plus an operation, good if you want multiplication and division too). If you want the same sums in a different shape, read on.
How Sumbriska works in 3 steps
- 1Read the tag. The small tag above each island is its target, like a Kakuro clue. The big number is what it has now: the sum of the bridge ends that touch it.
- 2Flip a bridge. Each bridge carries two numbers, one per end. A flip swaps them, so one island gains exactly what its neighbour loses.
- 3Balance every island. When all tags are met the board is solved. Moves count against a par, and three stars mark a tidy route.
Kakuro asks "which digits fit this run?"; Sumbriska asks "which way should this bridge face?"
Your first week: a Kakuro solver's plan
Everything here is in the free download. Each day lists the Kakuro habit that does the work, so you can see what transfers.
| Day | Where and what | Kakuro habit it uses |
|---|---|---|
| Day 1 | Practice, GentleLearn the flip. Read the tag (target) and the big number (current) on every island. | Reading a clue before writing |
| Day 2 | Practice, SteadyFind the island with the fewest bridges; it has the fewest possible totals. | Starting from the shortest run |
| Day 3 | Logic Lens onUse the gap numbers (+3, -5) the Lens shows instead of pencil marks. | Clue minus what's filled in |
| Day 4 | Lantern HarborStart region 1. Solved boards build your island. | A new book of puzzles |
| Day 5 | Daily boardSame idea every day: one board, then stop. | The newspaper Kakuro |
| Day 6 | Clever + Two TidesOne layout, two tide schedules. Like a run that has to work across and down. | Crossing runs that must agree |
| Day 7 | The DeepAn endless dive for a long evening. Harbor Run if you want a clock. | A thick puzzle book |
Kakuro skills that carry over (and two that don't)
- Start at the tightest spot. In Kakuro you look for a 3-in-two or a 4-in-two. Here, an island touched by one bridge has only two possible totals, so that bridge is usually decided first.
- Work from the gap. Clue minus what's filled in becomes target minus current. A 2|5 bridge swings each end by 3, so it's the answer when an island is exactly 3 off.
- Crossing runs must agree. The Kakuro intersection becomes a shared bridge: whatever it gives one island, it takes from the other.
- Doesn't carry: combination tables. You never choose digits, so knowing every sum set by heart won't help.
- Doesn't carry: heavy pencil marks. A bridge only faces two ways. The Logic Lens shows each island's gap, which does the job pencil marks used to.
Who Sumbriska is not for
If what you love in Kakuro is the combination work, the joy of knowing 34 in five is 4, 6, 7, 8, 9, Killer Sudoku will feel more like home. If you want a large printed grid on a coffee table, a phone game isn't it. And if you only play on Android, Sumbriska is iPhone only. It's for people who like the arithmetic of target sums and want a calmer, cleaner board to do it on.
Questions Kakuro players ask
What games are like Kakuro?
Anything where every move is checked against a target sum. On paper that means Killer Sudoku (cage sums inside a sudoku) and KenKen-style puzzles (cages with a target and an operation). On iPhone, Sumbriska keeps the target sums but swaps the grid for islands and bridges: one flip changes two totals at once.
Is Sumbriska harder than Kakuro?
It asks for a different kind of thinking rather than more of it. Kakuro is about which digits can fill a run; Sumbriska is about which way each bridge faces. Gentle boards use small numbers and a few bridges, and Clever and Deep boards ask you to plan several flips ahead.
Do my Kakuro combinations still help?
The habit does, the tables don't. You won't need to know that 17 in two is 8 and 9, but you will keep asking 'how far is this island from its target, and which bridges can close that gap?'
Is Sumbriska free?
The free download includes regions 1 and 2, the Daily board, The Deep and Harbor Run, with no ads. The optional Voyage Pass ($4.99 a month or $29.99 a year, no free trial) adds regions 3 to 6, all side boards, Gale Run, the 3-4 ring workshop and premium cosmetics.
Can I play without a timer?
Harbor Run is the mode built around a clock. The listing describes the rest of the game as boards that reward careful, unhurried thinking, with moves counted against a par rather than a countdown.
Does it work offline, without an account?
Yes. It works fully offline, needs no account and, according to its listing, collects no data.
Honest limits
- Regions 3 to 6, side boards such as Shipyard and Observatory, Gale Run and the 3-4 ring workshop need the Voyage Pass. There's no free trial, so judge it on the free regions first.
- The free content is generous for a first week, but heavy solvers will reach the end of regions 1 and 2. The Daily board and The Deep keep going.
- A design decision we made: hints, Undo and step explanations never cost XP. Some Kakuro purists will find that too forgiving; you can simply not tap them.
Try it tonight
One Gentle board, one Steady board, then the Daily. Twenty minutes and you'll know whether bridges scratch the Kakuro itch. Try it tonight, free on iPhone.
Related
- Sumbriska: the number bridge puzzleFlip bridges until every island hits its exact sum. A calm number bridge puzzle for iPhone: no ads, offline, two regions free.
- What to play after sudoku: a first-week guide to SumbriskaBored of sudoku? Sort which sudoku habits carry over, then follow a 7-day first week in Sumbriska, a number bridge puzzle. Free on iPhone, no ads.
- Number puzzles for adults who think they're bad at mathFreeze at numbers? A three-tap quiz picks your starting board, and we show every sum a real Sumbriska solve needs. No timer, no ads.
- Free bridges puzzle apps with no ads, comparedFour bridges (Hashi) puzzle apps for iPhone checked against their App Store listings: price, ads, what is free and what costs extra.