Solid Sudoku: Daily Puzzle

doorgames.io

In-app purchases

About this game

A sudoku, not a platform.

Solid Sudoku is a classic sudoku game: 9x9 sudoku puzzles with a daily challenge — calm, paper-styled logic puzzles, fully playable offline. Open the app, pick a difficulty, play.

Try everything free for 7 days. One small unlock keeps the whole game. No ads, ever. Nothing else to buy.

A REAL LOGIC PUZZLE

Every puzzle is generated on your device and always has exactly one solution — a real brain game, solvable by deduction, never by guessing. Four difficulty levels run from a gentle Easy to a properly stubborn Expert.

DAILY CHALLENGE

A daily sudoku, identical for every player in the world. Solve today's grid and see how your time stacks up — an anonymous percentile against everyone else who played. No account. No usernames. Just the number. Keep a streak going on the calendar — a day counts at any difficulty, so your streak is about showing up, not about speed. An optional daily reminder keeps it alive.

THE TOOLS YOU'D ACTUALLY USE

• Notes mode for pencil marks — cleared automatically when you fill the cell
• 3 hints per game, each one explaining the solving technique it used. A hint adds 30 seconds to your adjusted time, so a solved grid still means something
• Full undo and redo — the move history even walks back hints and mistakes honestly
• Optional error highlighting — flag wrong entries and rule conflicts, or switch it off and trust your logic
• Smart highlighting for the selected row, column, box, and matching numbers
• The number pad counts down how many of each digit are left

DESIGNED LIKE PAPER

The whole aesthetic is called Clean Paper: a warm white page, clues that look printed, your entries in soft blue ink. A fresh puzzle page every game, with a touch of retro pixel charm at launch.

NO INTERNET REQUIRED

Fully playable offline. On a plane. In a basement. Puzzles are generated on your device — no WiFi, no cellular, no waiting for a server. Even today's Daily Challenge works offline; only the percentile needs a connection. Your game saves itself and resumes exactly where you left off. Offline sudoku, start to finish.

ONE HONEST UNLOCK

The whole game is free for 7 days — every difficulty, every tool, nothing held back. If it earns a spot on your home screen, one unlock keeps it: a small yearly subscription or a one-time lifetime purchase. No ads, ever. Nothing else to buy. No account, no sign-in — purchases use anonymous store IDs, there's no ad tracking, and your data is never sold.

A LITTLE STOIC CALM

Stoic quotes from Marcus Aurelius, Epictetus, and Seneca rotate through the app. A small moment of philosophy before the logic starts.

SUDOKU FEATURES

• Classic 9x9 sudoku puzzles — a number puzzle with four difficulties: Easy, Medium, Hard, Expert
• Daily Challenge — the same seeded puzzle for everyone, every day
• Unique-solution puzzles, generated instantly on device
• Pencil marks, hints, undo/redo, error checking
• Pause-aware timer — pausing never costs you time
• Three mistakes and the round is over — gentle stakes, honest wins
• Auto-save and resume across launches
• Works with a hardware keyboard — arrows, digits, shortcuts
• Streak calendar with an optional daily reminder
• Number lock — pin a digit and place it across the grid
• Remaining counts under every digit on the number pad
• Statistics dashboard — win rate, streaks, solve-time trend
• Dark and light themes, plus a high-contrast mode

The whole sudoku game, right here. Pick a difficulty. Fill the grid. That's it.

What’s new

A bigger board. The line under the number tray is gone and its space goes to the board, and on tablets, foldables and split screen the tools now stand beside the board instead of below it.

Small phones got a careful pass too: the pause and hint buttons can no longer be squeezed out, and the title no longer runs into the clock.

• A bigger board on most screens
• Tools beside the board on tablets and split screen
• Smaller fixes and polish throughout

Still no ads, no ad tracking, no account.