The premise Most mobile games compete on stimulation: timers, streaks, daily missions, push notifications. We wanted to go the opposite direction. Off By One has exactly one mechanic: a grid of near-identical geometric shapes, one slightly wrong. Find it. No countdown. No lives. No nudge to come back tomorrow. How it works technically Drawing is handled by SwiftUI Canvas. Shapes and decorations are procedurally generated — around 133,200 combinations — so the same stage looks different on each attempt. 35 stages across Easy, Normal, and Hard. 17 Game Center achievements for players who want a concrete goal. iOS 16+ required. The variation isn't cosmetic. On Hard, the grid is dense enough that the wrong shape can sit unnoticed for a while. Increasing grid density was the primary difficulty lever. What works Players who sit with it tend to describe it as calming — which was the exact feeling we were building toward. Removing urgency mechanics changes the texture of the experience more than we expected.…