The problem we were solving
Most puzzle games are anxiety games in disguise. The mechanic is fine, but a timer layer, a combo meter, or a decaying score turns what should be observation into a race. You stop looking and start rushing.
We wanted to build the opposite.
What the app does
Off By One shows a grid of geometric shapes. They all look identical — but one is slightly off. A different form, a subtly different decoration, a slight rotation. Your job is to find it and tap it.
No timer. No countdown. No penalty for being slow. Just observation.
There are 35 stages across Easy, Normal, and Hard difficulty. Shapes and decorations are procedurally generated from about 133,200 combinations, so the board stays varied across sessions. Built on SwiftUI's Canvas API, iOS 16+. Game Center is integrated with 17 achievements — structured to reward progress without leaning on score pressure.
What we learned shipping it
The hardest part wasn't the procedural generation. It was the App Store preview. You get a few seconds of footage to convince someone to install, and a near-static puzzle screen that's deliberately calm is genuinely difficult to sell in motion. The appeal lives inside the experience, not in watching it scroll by.
We also haven't implemented IAP yet. The app is free with reward ads only — which puts a ceiling on how we reach puzzle players who'd pay to remove ads. That's on the list.
Try it
Free on the App Store: https://apps.apple.com/jp/app/id6762133251
Hard difficulty is harder than it looks in the first few stages. Curious whether that curve lands right.
