Monostroke vs Missing Digits

Monostroke is a single-line drawing puzzle. Draw one continuous stroke through every required cell — no lifting your finger, no retracing your path. One simple rule. A lot of depth. ONE RULE. WORLDS OF DEPTH. Start with the basics. Then meet the mechanics, one at a time: • Walls block your path. • Ice slides you in straight lines. • Switches flip the rules mid-stroke. • Portals teleport across the board. • Veils hide what lies beneath. • Bridges let your line cross itself, cleanly. Every mechanic is taught before it's tested. THREE CHALLENGE MODES For when the basics feel too tame: • MIRROR — your stroke mirrors across an axis. • BLUEPRINT — strict, minimalist puzzles for the precise. • TALLY — hit every checkpoint as you go. Master a world to permanently unlock its visual theme. THE GAUNTLET Five floors. No retries. The line ends here. The Gauntlet is the prestige test. Earn shards from your runs and spend them on the most exclusive cosmetic in the game: the iridescent Aurora theme. META-MAPS Each region of a hand-drawn world is its own puzzle. Together, they form a complete map. Solve every sub-region of the Hourglass to complete the picture. EARN WHAT YOU WEAR Themes are unlocked through play, not paywalls. Master a world to claim its visual identity: • Paperweight — aged manuscript paper. • Tron — neon on dark glass (cyan, orange, magenta variants). • Constellation — cosmic starfields with optional aurora overlays. • Blueprint Cyanotype — drafting-paper aesthetic. • Wood — polished go-board. • Aurora · Iridescent — the prestige tier, earned with Gauntlet shards. Plus path skins, endpoint markers, and checkpoint markers — all earned in-game. THOUGHTFUL PLAY No timers on regular puzzles. No daily streaks to break. Sketch a route, retract, try again. The puzzle waits. Free to play, with optional rewarded ads. A one-time Premium purchase removes all ads and unlocks bonus coins plus a cosmetic starter pack.

Guessing won't fill the blanks. Logic will. Follow the carry from the ones column, and every hidden digit narrows to a single answer. Missing-digit arithmetic and classic cryptarithms, in one quiet app. • Free to start. No subscription • No third-party ads • Your records stay on this device ■ Your first puzzle Your first puzzle walks you through it, one column at a time. No need to know the rules. You can replay it anytime from How to Play in Settings. ■ Missing digits Part of a written sum is hidden. Fill in the blanks so the arithmetic works. • Easy: column addition • Normal: addition and single-digit multiplication, chosen so you can't just subtract your way through • Hard: long multiplication with partial products • Oni: 4×3-digit and 5×2-digit long multiplication Puzzles are generated on your device, so you never run out. ■ Cryptarithms Letters stand for digits, as in SEND + MORE = MONEY. Same letter, same digit; different letters, different digits. 119 puzzles built from everyday English words. ■ Exactly one answer Each puzzle starts as a completed sum, and digits are hidden only while a single answer remains. Every cryptarithm was chosen because it has one solution. ■ Today's puzzle and ranks One puzzle a day, the same for everyone. Weekdays are Normal; weekends are Hard long multiplication. Earn points as you solve and climb from 10th Kyu to Master. Your streak and a calendar keep your history visible. ■ Quiet help • Columns that can't work out are gently tinted (you can turn this off) • If you're truly stuck, a hint reveals a single cell ■ Chalk on a blackboard Deep green board, chalk-white digits, set vertically the way you'd write by hand. The board lights up gold when you solve it. On iPhone and iPad, the board grows to fit your screen. ■ Great for • Sudoku and crossword fans who want puzzles that actually use arithmetic • Anyone who'd rather deduce than drill • Kids preparing for entrance exams, and their parents • Building a small daily brain-training habit • Playing on planes and trains with no signal ■ Privacy • No account required • Puzzles are created inside the app; no connection needed to play • No tracking • To show other apps by the same developer, the app reads public App Store listings only. None of your data is sent