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About
A daily brain puzzle where you place stars in a starry night sky. One puzzle per day, the same for everyone in the world.
▣ THE RULES (3 lines, infinite depth)
A modern take on Star Battle, also known as "Two Not Touch":
• Place K stars in each row
• Place K stars in each column
• Place K stars in each bold-bordered region
• Stars cannot touch — not horizontally, vertically, or diagonally
That's it. Three rules. But the deduction chains run deep.
▣ MODES
• Daily Challenge — A new 10×10 Expert puzzle at midnight UTC. Everyone in the world solves the same one. Build your streak.
• Custom Play — Pick your size (5×5 to 10×10) and difficulty (Easy → Master). Five tiers of brain-bending.
• Resume Anywhere — Your in-progress game auto-saves. Pick up where you left off.
▣ NO AD HARASSMENT
• Daily Challenge is always ad-free
• Get a hint by watching one short ad — that's it
• Remove ads forever with a single one-time purchase
• No subscriptions, no upsells, no "premium tier"
▣ THIS IS FOR YOU IF
• You've solved Killer Sudoku Expert and want the next step
• You love NYT Games' "Two Not Touch" puzzles
• You miss the long deduction chains of Nikoli-style puzzles
• You want a focused 5 to 30 minutes a day for your brain
▣ TOOLS THAT RESPECT YOUR TIME
• Three input modes — Star, X-mark, Eraser — never more than one tap to switch
• Drag in X mode to paint multiple cells in one motion
• Unlimited Undo / Redo
• Instant red highlight when a placement violates the rules
• Hint system reveals one correct star at a time (via short reward ad)
▣ TRACK YOUR PROGRESS
• Solving time and total completions
• Best time per grid size
• Current streak and longest streak
• Compare your record against the global average
▣ MADE IN KOREA
Independent puzzle studio. Built for people who actually solve hard puzzles, not "casual brain games.
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What's New in Byul
1.0
June 4, 2026
1
In-App Purchases
$9.99
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Permanently removes all advertisements. Single purchase





