#game

Sudoku

A single-file Sudoku puzzle rendered in the same picture-book aesthetic as Snake, Watermelon Game, and Pencil Hit (warm dark-brown outlines, pastel fills, rounded board, Fredoka + Jua typography). A clean 9×9 grid with a calm sky-blue accent — pick a level, fill the grid so every row, column, and 3×3 box holds 1–9, and race your best time without burning through your three mistakes.

How to Play

1. On the start panel choose a level — Easy, Medium, or Hard — then tap GAME START.
2. Tap a cell to select it. Its row, column, and box are highlighted, and every matching number lights up.
3. Tap a number on the 1–9 pad (or press a number key) to fill the selected cell.
4. A correct entry turns blue; a wrong one turns red and costs a mistake. Three mistakes ends the game.
5. Solve the whole grid correctly to win — the faster you finish, the better your time.
6. Tap Play Again on the result screen, or 🏠 Home to pick a different level.

Features

Three Difficulty Levels

Each level starts from a different number of clues — Easy (44), Medium (34), Hard (28) — and every puzzle is generated fresh with a guaranteed unique solution (clues are only removed while exactly one solution remains).

Smart Highlighting

Selecting a cell highlights its peers (same row, column, and 3×3 box) in a faint cream, and lights up every other cell holding the same number in amber — so spotting placements and conflicts is effortless.

Pencil Notes

Toggle ✏️ Notes to drop small candidate numbers into a cell — a 3×3 mini-grid, just like pencilling in a paper Sudoku. Placing a confirmed number automatically clears that candidate from its peers.

Mistakes & Hints

• A mistake counter (x / 3) tracks wrong entries; the third mistake ends the run.
• 💡 Hint (3 per game) reveals the correct number in the selected cell and locks it in.
• ⌫ Erase clears your entry or notes from a cell; ↩️ Undo steps back through your moves.
• The number pad shows how many of each digit are still left to place, and dims a digit once all nine are down.

Best-Time Persistence

Your fastest solve is stored per level in the browser. Beating it shows a ✨ New Best ✨ flourish on the win screen.

Sound Effects

All sounds are synthesized on the fly — no external files.

• Soft tick on selecting a cell and on jotting a note.
• Gentle chime when a correct number lands.
• Short buzz on a wrong entry.
• Two-note sparkle on a hint, a rising four-note fanfare on solving, and a descending arpeggio when you run out of moves.

A 🔊 / 🔇 mute button silences everything. Audio auto-resumes when the page returns from background.

Quality-of-Life Details

Two icon buttons sit below the playfield:

• 🔊 / 🔇 Mute (bottom-left): Silence all sound.
• 🏠 Home (bottom-right): Return to the level-select screen.

Other niceties:

• Touch + keyboard — tap cells and the pad on phone, or use number keys, Backspace/Delete to erase, N to toggle notes, and arrow keys to move the selection on desktop.
• A correct placement instantly clears stale notes from the rest of its row, column, and box.
• Live count-up timer and game-over / win overlays styled like the sibling games.

Design

• Portrait page (9:16) with a square 9×9 board — fits entirely on a phone without scrolling.
• Cream board with dark-brown outlines — thin tan lines between cells, bold brown lines between the 3×3 boxes, matching the sibling games' hand-drawn picture-book feel.
• Fully rounded board corners.
• Sky-blue start / restart buttons and pads with a layered inset shadow for a 3D pressable look — the calm, logical counterpart to Snake's green and Pencil Hit's yellow.
• Blue user entries vs. brown clues so what you placed always reads apart from the puzzle's givens.
• Fredoka + Jua font (Google Fonts) for a rounded, child-friendly look.

Tech

• Single HTML file — no build step, no external assets (except a single Google Fonts link).
• DOM-based 9×9 grid for crisp number rendering, instant highlighting, and pencil notes.
• Backtracking generator + solver that fills a random full grid, then removes clues while a uniqueness check (solution count capped at 2) confirms the puzzle stays unique.
• Web Audio API for all sound — synthesized tones, no audio files.