Pencilled In

Pencilled In is Sudoku the way it feels on paper: a good sheet under a warm desk lamp, the grid printed in ink, and every number you write drawn in pencil, stroke by stroke. Every puzzle is made fresh, has exactly one answer and can be solved by logic alone, and is graded by the techniques it takes, from Gentle through Easy, Medium and Tricky to Expert's wings and swordfish. There's a new Daily Puzzle every day, with a streak to keep.

Rub a number out and the eraser leaves a faint smudge and a few crumbs. A number that doesn't belong is circled in red pencil (or not, if you'd rather). Finish a row and a highlighter sweeps along it; finish a box and it's ruled round in pencil; finish the puzzle and your answers are inked over, the page is stamped Solved, and the next sheet slides in.

Stuck? Hints show you where to look first, then explain why, naming the technique and lighting up the squares that prove it, and they'll fill the answer in if you'd like. Pencil in notes (they tidy themselves as you place numbers), undo and redo anything, and everything saves as you go.

It's easy on the eyes: big, crisp numbers, three text sizes, a high-contrast mode, graphite or blue pencil, highlights that are safe for colour blindness, and no clock unless you want one. Every solve is kept, stamped and dated, in your Puzzle Book, and your pencil grade softens from 9H towards 9B as you go. A quiet piano and rain on the window play along, every sound made for the game.