Rocky's Mine Sudoku 돌돌이의 광산 스도쿠
Sort the gem crates with Rocky the golem, keeper of the Demon King's mine. Five difficulties from Beginner to Expert, 2,000 stages.
About the game
Rocky's Mine Sudoku is the story of Rocky, the golem who keeps the mine under the Demon King's castle in Gate Guard. The gem crates in the mine are numbered 1 to 9, and Rocky has to sort them so no number appears twice in any row, column or 3×3 box. Rocky is slow, but never gives up once started — fill in the grid step by step together.
There are five difficulties — Beginner, Easy, Medium, Hard and Expert — each with 400 stages that unlock in order. Every puzzle has exactly one solution and was solved ahead of time the way a person would, then scored by how hard it is. Stages get a little harder as you go, and stage 200 of one difficulty is about as hard as the first stage of the next, so there are no sudden walls. From stage 201 on, challenge stages keep getting harder with the same techniques.
Solve with at most one mistake or hint to earn 3 stars. Your game is saved automatically, so you can pick up where you left off anytime.
How to play
- Pick a cell
- Tap a cell to select it. Its row, column, box and matching numbers are highlighted. On PC, move with the arrow keys.
- Enter a number
- Tap the number pad (keys 1–9 on PC) to fill the selected cell. Wrong numbers turn red and count as mistakes.
- Notes
- Turn on ✏️ Notes (N) to jot down small candidate numbers. When you place a correct number, it's cleared from the notes in the same row, column and box.
- Undo · Erase · Hint
- ↶ Undo (Z), ⌫ Erase (0 · Backspace), 💡 Hint (H). A hint fills the selected cell, or an empty cell that's easy to solve next.
Guide
- 🌱 Beginner
- Lots of numbers are filled in — just find cells where only one number fits. Start here if Sudoku is new to you.
- 🟢 Easy
- You'll also need to spot when a number can only go in one cell of a row, column or box.
- 🔵 Medium
- Solved the same way as Easy, but with many more empty cells.
- 🟣 Hard
- You'll need candidate pairs, or spot when a number in a box can only go in one row.
- 🔴 Expert
- Uses Hard techniques many times, or needs advanced ones like candidate triples and the X-Wing. Use notes a lot.
Tips
- The small number under each key shows how many of that number are left. Start with the numbers that are almost done.
- If a number can only go in one cell of a row, column or box, that cell is the answer.
- From Hard on, turn on notes and write down candidates — the hidden patterns become much easier to see.
- You get 3 stars with at most one mistake or hint. Mistakes never end the game, so feel free to try.