X vs Untangled Ropes

X-Sudoku — Logic Puzzles Game Train your mind with the most elegant puzzle game on the App Store. X-Sudoku offers hundreds of hand-graded puzzles across two distinct variants, built for players from first-timers to seasoned solvers. Two Variants. One Obsession. Classic 9×9 — The timeless grid. Fill every row, column, and 3×3 box with the digits 1 through 9. Pure logic. No guessing required. X-Sudoku — An additional twist: both main diagonals must also contain all nine digits. 18 extra constraints. Entirely new strategies. Five Difficulty Levels From Easy (~10 min) to Epic (~45+ min), each difficulty unlocks as you progress. Whether you have a few minutes or a long commute, there's a puzzle for you. Earn Points. Climb Titles. Every solve earns points based on your speed, mistakes, and streak. Rise through 20 titles — from Student to Immortal. Daily Challenges A fresh puzzle every day. Solve it to earn bonus points. Keep a 7-day streak to double your daily rewards. Perks System Earn perks by solving puzzles: use a Hint to reveal a cell, Chance for an extra mistake, Forgive to wipe your record clean, or Double Points to maximise your score. Clean. Focused. No clutter. Elegant typography, a paper-toned palette, and smooth animations keep the focus on the puzzle. Visit our website for more information and our privacy policy: https://x-sudoku.com/privacy/

A knot of crossing lines. Drag them until none of them touch. That's it. That's the whole game. And still there are 2500 levels in every mode, and never the same one twice. FOUR MODES • Classic — Endless levels, difficulty creeping up. • Zen — No clock, no pressure, and a progression of its own. • Challenge — Knots can't cross ropes, so you have to work your way through. • Einstein — Counted moves. Think before you touch. ALSO • 34 achievements, bronze to gold. • Three challenges on every level: no hints, against the clock, no undo. • Coins for finishing levels, and a shop of knot shapes and colour palettes. • Statistics: best time, day streak, crossings undone. • Works offline. No account, no sign-up. • In English, Spanish, Catalan, Portuguese and French. Ads are voluntary: one only shows if you choose to watch it for coins. "To undo a knot, first you have to understand it."