The short version
This Sudoku doesn't try to reinvent a puzzle format that's over a century old — it just implements it cleanly, with three difficulty tiers, a notes mode for pencil marks, a hint system, and a full auto-solver, and gets the one thing this shelf cares about most exactly right. Testing confirmed, with a real emulated touchscreen, that tapping an empty cell selects it and tapping a number on the on-screen pad places it — cleanly, correctly, and with clear visual feedback at every step. It's built on creator Frank Force's own LittleJS engine, the same toolkit behind several well-regarded js13k entries, and it shows: the whole thing loads instantly, ran without a single error across every test performed, and never once asked a touch player to reach for a keyboard.
Biggest strengths
- The core interaction was tested directly rather than assumed: a real touchscreen tap correctly selected an empty cell (with clear highlight feedback), and a real tap on the on-screen number pad correctly placed the chosen digit, confirmed visually across multiple cells and multiple puzzles
- A genuinely complete feature set for a puzzle this classic — three difficulty levels, a notes mode for pencil marks, a hint button, and a full auto-solve option, all reachable through the same on-screen button row that handles ordinary play
- Desktop parity confirmed separately: mouse clicks correctly select cells, and the interface displays keyboard shortcut hints (1-9 to place, N for notes, H for hint, R for a new puzzle) for players who prefer a keyboard, without ever making touch feel like the secondary option
Biggest weaknesses
- This is Sudoku; the format itself has had no fundamental changes in decades, and nothing here is trying to add one, so there's no novelty to speak of beyond a well-made implementation of a very familiar puzzle
- The visual design, while clean and legible, is a fairly generic dark-with-neon-accent theme shared by the look of this creator's other arcade games, rather than something distinctively its own
- Difficulty is limited to three broad tiers (Easy, Medium, Hard) with no finer control or seeded-puzzle sharing, which some dedicated Sudoku players may find limiting compared to apps built specifically around the format
Who it's for: Sudoku players who want a fast, ad-free, no-nonsense version that works properly on a phone
Our recommendation: Worth keeping on hand as a genuinely reliable phone Sudoku — nothing flashy, just correct
8 / 10
There isn't much mystery left in Sudoku as a format, so the fair question for any new implementation is simply: does it get the basics right, and does it work properly on the device you're actually holding? This one does, on both counts. Three difficulty settings generate a fresh random puzzle each time, and the toolset around the grid — pencil-mark notes, a hint that reveals one cell without spoiling the rest, and a full auto-solve for when you're done experimenting — covers everything a Sudoku player expects without adding anything gimmicky on top.
Touch confirmed properly, not just claimed
The interaction model here is worth describing precisely, because it was tested rather than taken on faith. Selecting a cell and placing a number are two separate actions, and both were confirmed directly with a real emulated touchscreen: tapping an empty square on the grid selects it, shown by a clear colour highlight, and a subsequent tap on the on-screen number row places that digit into the selected cell — visually confirmed by watching the numeral appear and the corresponding number-pad button grey out to reflect the board's now-complete count of that digit. This was repeated across multiple cells and multiple freshly-generated puzzles with consistent results. Desktop testing confirmed the same selection behaviour with a real mouse click, and the interface separately displays keyboard shortcuts (1 through 9 to place a digit, N for notes, H for hint, R for a new puzzle) for players who want them — but nothing about the design assumes a keyboard is present, which is exactly the bar this shelf holds every game to.
A generic, well-built implementation
There's an honest trade-off in awarding a high score to something this unoriginal: nothing about this Sudoku is trying to be memorable. The dark, neon-blue-accented interface is clean and legible but shares its visual identity closely with the creator's other games in the same collection, and the puzzle format itself hasn't meaningfully changed since long before the web existed. What earns this a strong score anyway is execution: it's built on Frank Force's own LittleJS engine — the same toolkit behind several well-regarded js13k competition entries — and it shows in the stability. Every test performed across both device profiles came back completely clean, with no console errors, no page errors, and no failed network requests of any kind.
Final verdict
This won't surprise anyone who's played Sudoku before, and it isn't trying to. What it offers instead is a genuinely reliable, fully touch-functional implementation with real depth in its support tools (notes, hints, auto-solve) and a clean bill of technical health across every test run. For a shelf built around the promise that a game actually works on the phone it's opened on, a puzzle this classic, executed this cleanly, earns its place.
Pros and cons
Pros
- The core interaction was tested directly rather than assumed: a real touchscreen tap correctly selected an empty cell (with clear highlight feedback), and a real tap on the on-screen number pad correctly placed the chosen digit, confirmed visually across multiple cells and multiple puzzles
- A genuinely complete feature set for a puzzle this classic — three difficulty levels, a notes mode for pencil marks, a hint button, and a full auto-solve option, all reachable through the same on-screen button row that handles ordinary play
- Desktop parity confirmed separately: mouse clicks correctly select cells, and the interface displays keyboard shortcut hints (1-9 to place, N for notes, H for hint, R for a new puzzle) for players who prefer a keyboard, without ever making touch feel like the secondary option
- Zero console errors, zero page errors, and zero failed requests across every test run on both device profiles — a clean, stable implementation
- Free, MIT-licensed, and part of an actively maintained collection (the parent repository was updated within the last week at the time of this review), rather than an abandoned one-off
Cons
- This is Sudoku; the format itself has had no fundamental changes in decades, and nothing here is trying to add one, so there's no novelty to speak of beyond a well-made implementation of a very familiar puzzle
- The visual design, while clean and legible, is a fairly generic dark-with-neon-accent theme shared by the look of this creator's other arcade games, rather than something distinctively its own
- Difficulty is limited to three broad tiers (Easy, Medium, Hard) with no finer control or seeded-puzzle sharing, which some dedicated Sudoku players may find limiting compared to apps built specifically around the format