We built a puzzle game about noticing the one thing that's wrong

#ios #swift #gamedev #indiedev

There's a specific kind of satisfaction in noticing something is wrong before you can explain why.

You're looking at a grid of geometric shapes. Each one appears identical. But one isn't — something in the rotation, the scale, the position is fractionally off. The moment you see it, you can't unsee it.

That's the experience we were after when we built Off By One.

What we were trying to solve

Most puzzle games ask you to be fast, or to remember things, or to react. We wanted to build something that rewarded sustained attention instead — the kind of calm, patient looking you do when you're proofreading or checking a design for alignment errors.

Off By One strips everything else away. No timer running in the corner. No score multiplier. No story. Just a grid and a small wrongness hiding inside it.

How the puzzles are generated

We use SwiftUI's Canvas API for rendering. Shape type, decoration pattern, and placement are combined procedurally — about 133,200 possible combinations. The practical effect: replaying a stage rarely gives you the same puzzle twice, which matters for a game with no narrative carrying you forward.

Three difficulty levels across 35 stages. On Easy, the off element is clearly different. On Hard, you're looking for a rotation difference that's genuinely subtle — the kind that makes you second-guess yourself before you commit. Game Center tracks progress with 17 achievements.

Honest limitations

The 6-second App Store preview video is a real problem for us. "Quiet observation" doesn't compress into a clip. We've watched people look at the preview and not understand what the game is — a legitimate discovery issue we haven't solved.

We also haven't implemented in-app purchase. The app is free with rewarded ads only, which means users who genuinely love it have no way to pay for an upgrade. That gap is on us.