suuudokuuu vs ECHO LOOP

suuudokuuu is Sudoku the way it should be: fast, beautiful, and honest about difficulty. Seven levels, from a gentle Newbie board to Infinity — the hardest Sudoku puzzles ever composed. No ads pretending to be puzzles, no accounts, no nonsense. Just you and the grid. EVERY PUZZLE, RATED Most apps label a board "expert" and hope you don't look closer. We put a number on it. Every puzzle carries a Sudoku Explainer rating on the 1.0 to 12.0 scale serious solvers use, shown right in the level pill on the board, in your history, and on every link you share. A built-in explainer tells you what the number actually measures — how hard the puzzle is to reason through, not how few clues it has. INFINITY: THE WORLD'S HARDEST SUDOKU A curated set of 100 world-record puzzles rated SE 10.4 to 11.9. Arto Inkala's Everest and AI Escargot. Golden Nugget. Platinum Blonde. Kolk, Patience, Fata Morgana, Red Dwarf. These are the grids the solving community made famous, and most people never finish one. HELL, RE-CURATED Hell is now 1,544 verified 17-clue puzzles, every one rated SE 6.6 or higher. Seventeen clues is the fewest a Sudoku can have and still have exactly one solution — but a low clue count alone doesn't make a puzzle hard, so we rated the whole corpus and kept only the boards that fight back. YOUR SOLVING, MEASURED The redesigned statistics screen shows your hardest solve, your recent average difficulty and the level you play most. The SE spectrum plots every puzzle you've finished across the scale. Your arsenal counts every technique you've actually used — naked pairs, X-Wing, swordfish and further — so you can watch your repertoire grow. CHALLENGE A FRIEND Rival mode sends your exact puzzle to a friend as a share link, with your recorded run attached. They play the same grid you did and race your time move for move. Bragging rights, settled. WATCH IT BACK Every finished game replays move by move, and each history card carries a summary of the techniques that solved it. PLAY YOUR WAY Pick Classic, Gold or Newspaper, or open the live-preview theme editor and make every cell, line and highlight yours. Built-in contrast validation keeps custom themes readable in light and dark. On the web there's full keyboard control: arrows to move, digits to place, Space or N for pencil mode, Shift and a digit for candidate marks, A for auto-candidates. EVERYTHING ELSE YOU'D WANT • 7 difficulties, Newbie to Infinity • An SE difficulty rating on every puzzle • Full theme engine with light and dark support • Rival challenges via share link • Move-by-move replay with technique analysis • Technique-aware scoring • 13 languages • Works fully offline • No account, no sign-up, ever • Free and open-source suuudokuuu is built for people who actually love Sudoku, not people who want to be sold a subscription. Download it, pick a difficulty, and find out what your number is. Learn more at www.suuudokuuu.com.

The blocks you cleared come falling back. This is a falling-block puzzle where your toughest opponent is yourself. Every piece you place is recorded — and each time the clock loops around, it returns to the board in the same column, the same shape. Clearing lines alone won't save you: your own history piles up until it swallows the board. Clear lines through the returning shadows to erase their records for good and grow your score multiplier. How long can you hold back the tide of your own moves? Features - A run takes just a few minutes — perfect for short breaks - Easy controls: slide to move, tap to rotate, flick down to drop - No in-app purchases. Ads appear only occasionally on retry — never during play - A rule you won't find anywhere else: your moves become your enemies - Clear through the shadows to build your score multiplier - Works offline. Beat your best, then take on the world leaderboard