Sudoku Killer - Inveni

Inveni Apps

In-app purchases

About this game

Killer Sudoku is a logic puzzle game that combines classic sudoku with simple
arithmetic. Play offline, with four difficulty levels, pencil notes in every
cell, unlimited undo, and a puzzle generator that guarantees exactly one
solution to every board.

How Killer Sudoku works

The grid starts empty and the clues are sums. Each dashed area is a cage: the
digits inside it must add up to the small number in its corner, with no digit
repeating. Every rule of classic sudoku still applies, so each row, column and
3x3 block holds 1 through 9 exactly once. The variant is also known as sumdoku
or mathdoku, and it rewards logic rather than guesswork.

Every puzzle has one solution

Before a board reaches your screen it passes through a solver that confirms a
single valid answer exists. No ambiguous grids, no puzzles that can only be
finished by guessing.

Plays offline, no account needed

No sign-up, no email, no permissions. The game collects nothing and runs on a
plane, on the subway, or anywhere with no signal at all.

Features

- Four difficulty levels. Easy opens with a few anchor digits for players new
to the variant. Medium, Hard and Expert start from an empty grid.
- Cage combinations. Tap the equation bar to see every possible sum for the
selected cage, already adjusted for the digits you have entered.
- Pencil notes, with candidates cleared automatically across the row, column,
block and cage when you commit a digit.
- Unlimited undo and redo.
- Three hints per game, which replenish on their own as you play.
- Conflict highlighting you control: instant, on request, or off entirely. It
flags contradictions you could spot yourself and never reveals the solution.
- A timer you can hide.
- Automatic saving. Close the app mid-puzzle and pick it up whenever.
- Statistics per difficulty: games finished, best time and average.
- Light and dark themes.
- 16 languages.

Play at your own pace

There are no lives to lose, no timers forcing a restart, and no subscription.
Take an hour on one Expert grid if you feel like it.

Supporting the app is optional and cosmetic

A single one-time purchase unlocks extra board colours. That is all it does.
No difficulty, hint, note or gameplay feature sits behind it, and none ever
will.

New to Killer Sudoku

A short skippable tutorial covers the rules, and you can reopen it from
settings at any time. A useful opening technique: look for two-cell cages
totalling 3, 4, 16 or 17, since each of those has only one possible pair.

Made by Inveni Apps.
Questions or suggestions: [e-mail]