Sudoku Kingdom is a free sudoku puzzle app on Google Play in which you solve sudoku puzzles to earn crowns and climb ranks. It offers four difficulty levels (Easy, Normal, Hard and Extreme), a Daily Sudoku Challenge that adds one special puzzle per day, and helpful features such as notes, duplicate-number highlighting, hints and automatic checks.
What Is Sudoku Kingdom
Sudoku Kingdom (listed as "Sudoku Kingdom – Sudoku puzzle" on Google Play) is a free sudoku puzzle game for Android devices. Unlike bare-bones sudoku apps that simply serve up grids, Sudoku Kingdom wraps the classic number puzzle in a light progression system: you solve puzzles, earn crowns, and raise your rank as your crown count grows. If you have never played this classic logic puzzle, our sudoku puzzle book guide is a good offline starting point.
Its listing on Google Play recommends it for players looking for free sudoku puzzles, people who want a challenge, and anyone who wants to relax or clear their mind with number puzzles (Google Play, Sudoku Kingdom listing).
One thing to know before you download: the name "Sudoku Kingdom" is used by more than one product. This article focuses on the Android app, while a short disambiguation section near the end covers the same-name apps so you don't mix them up.
How the Crown and Rank System Works
The crown-and-rank loop is what gives Sudoku Kingdom its identity. Here's how it works, based on the game's official listing:
- You earn crowns by solving puzzles. Every completed sudoku puzzle awards crowns.
- The number of crowns depends on the level you solve. Harder levels reward more crowns, which gives you a reason to graduate from Easy to Extreme rather than coasting on simple grids.
- Your rank rises as you collect crowns. There is no stated maximum: the game's goal is simply to reach the highest rank you can.
The app also promises a sense of completion beyond the rank ladder. There are many puzzle stages in Sudoku Kingdom, and the listing teases "a final scene that only you can see after you have completed them" (Google Play, Sudoku Kingdom listing). In other words, there's a payoff for players who work through the full catalogue.
The Daily Sudoku Challenge
Sudoku Kingdom includes a Daily Sudoku Challenge that adds one special sudoku puzzle per day. The twist is its collection mechanic: if you clear the Daily Sudoku Challenge every day for a full month, you complete a "gorgeous collection" (Google Play, Sudoku Kingdom listing).
This is a simple but effective habit loop. Rather than a streak counter that punishes you for missing a day, the game rewards a completed month with a visual collection item — a nice incentive for a five-minute daily ritual.
Difficulty Levels
Sudoku Kingdom offers four difficulty levels. Here they are at a glance:
| Level | Best for | Crown reward |
|---|---|---|
| Easy | Beginners and relaxed play | Fewer crowns |
| Normal | Regular players warming up | Moderate crowns |
| Hard | Experienced solvers | More crowns |
| Extreme | Expert players who want a real test | Most crowns |
The exact crown counts per level aren't published in the app's listing, but the principle is clear: the tougher the puzzle, the greater the reward.
How to Play Sudoku Kingdom
If you've never played sudoku, the rules are easy to pick up — and our sudoku puzzle book guide is a good companion if you want to practise offline too. The objective is to fill a 9×9 grid so that each row, each column, and each of the nine 3×3 boxes contains the digits 1 to 9 exactly once. A few numbers are given as starting clues; your job is to work out the rest using logic alone.
Step-by-step basics
- Look at the grid. Start with the rows, columns and 3×3 boxes that already contain the most given numbers.
- Find cells with only one possibility. If a row already contains 1 through 8 except 5, the empty cell must be 5.
- Use elimination. For an empty cell, check which digits are already in its row, column and box. The digits that remain are your candidates.
- Try the app's Note feature. Sudoku Kingdom lets you jot candidate numbers into a cell as pencil marks — the standard way to track possibilities on harder grids.
- Check your work. The app's automatic checks and duplicate-number highlighting flag clashes early, so you catch mistakes before they snowball.
- Use a hint when stuck. Sudoku Kingdom's Hint feature enters the correct number in a blank cell. Use hints sparingly — they're best saved for genuine dead ends, since overusing them removes the satisfaction of solving.
- Complete the grid. When every row, column and box contains 1 to 9, the puzzle is solved and you earn your crowns.
Strategies and Tips for Climbing Ranks
Want to rise through the ranks efficiently? These tips apply directly to how Sudoku Kingdom is structured:
- Master Easy before chasing Hard. Fewer mistakes and faster completions build your crown count more reliably than struggling through levels beyond your skill.
- Use notes from the start. Pencil marks are the single most useful feature on Normal and above. Fill in candidates for any cell you're unsure about — it makes elimination far easier.
- Lean on highlighting. Sudoku Kingdom highlights duplicate numbers in a row, column or box. Scan with it frequently; catching a clash early saves far more time than backtracking later.
- Do the daily challenge every day. One puzzle a day keeps your skills sharp and, over a month, completes the collection — a free reward for consistency.
- Save hints for Extreme. On easier levels, brute-forcing through a hint feels like a waste. On Extreme puzzles, a well-timed hint can unblock an entire grid.
- Play in short, focused sessions. Sudoku rewards concentration: two sharp ten-minute sessions usually beat one distracted half hour.
Sudoku Kingdom vs Other Free Sudoku Apps
The table below compares it against typical competitors on the features the game's listing confirms.
| Feature | Sudoku Kingdom | Typical free sudoku apps |
|---|---|---|
| Difficulty levels | Four: Easy, Normal, Hard, Extreme | Usually four to six (often Easy/Medium/Hard/Expert) |
| Daily challenge | Yes — one special puzzle per day, with a monthly collection reward | Often yes, but rarely with a collection mechanic |
| Progression system | Crowns and ranks; harder puzzles earn more crowns | Varies — many have none, some use trophies or XP |
| Hints | Yes — enters the correct number in a blank cell | Usually yes |
| Notes (pencil marks) | Yes | Usually yes |
| Duplicate highlighting | Yes — across row, column and box | Often yes |
| Automatic checks | Yes | Varies |
| Price | Free | Usually free with ads or optional purchases |
What sets Sudoku Kingdom apart on paper is the crown-and-rank progression and the monthly collection for daily players — mechanics many free sudoku apps simply don't offer. Prefer a tougher variant once you've outgrown the Extreme level? Our Killer Sudoku guide explains the cage-based twist.
Where to Play and Is It Free
Sudoku Kingdom is free to download and play on Android via Google Play (package com.ohtegames.sudoku.kingdom). The listing describes it as a free sudoku puzzle game, with no mention of mandatory purchases to access the core puzzles, ranks or daily challenge (Google Play, Sudoku Kingdom listing).
A quick disambiguation: other apps called Sudoku Kingdom
The name "Sudoku Kingdom" isn't unique to the Android app. You may come across:
- "Sudoku Kingdom – Puzzles Game" for iOS, developed by Tuan Tran and released in July 2018. It's a separate app on the App Store, also free, and is not the same product as the Android app described here (Sockscap64, iOS game listing).
- A browser-based "Sudoku Kingdom" listed in game databases such as IGDB, described as a free browser sudoku — another different product.
If you're an Android user looking for the crown-and-rank game with the Daily Sudoku Challenge, the Google Play listing is the one you want.
Is Sudoku Kingdom free?
Yes. Sudoku Kingdom is a free sudoku puzzle game on Google Play, and its core features — puzzles, crowns, ranks and the Daily Sudoku Challenge — are described as free in the official listing.
How do crowns work in Sudoku Kingdom?
You earn crowns by solving sudoku puzzles. The number you receive depends on the puzzle’s difficulty, and as you collect crowns your rank increases.
What happens in the Daily Sudoku Challenge?
Each day, the game adds one special sudoku puzzle. Clear it every day for a month and you’ll complete a collection reward.
Which devices can I play Sudoku Kingdom on?
The app described in this article is available on Android through Google Play. A separate same-name app, “Sudoku Kingdom – Puzzles Game” by Tuan Tran, exists for iPhone and iPad on the App Store.
Is there more than one app called Sudoku Kingdom?
Yes. The Android app on Google Play, an iOS app by Tuan Tran (2018), and a free browser sudoku listed in game databases all use the name. They are different products, so check the store before downloading.
What difficulty levels does Sudoku Kingdom have?
Four: Easy, Normal, Hard and Extreme. Harder levels award more crowns per solved puzzle.
Does Sudoku Kingdom have hints and notes?
Yes. The app includes a Hint feature that enters the correct number in a blank cell, a Note feature for jotting candidate numbers in cells, duplicate-number highlighting across rows, columns and boxes, and automatic checks to catch mistakes.