One Line Shift

Hold a dot. Drag along the lines. Cover every path exactly once. That is the whole rule — and it is enough to leave you stuck for ten minutes, then see it all at once. It is a hard game — not because it rushes you, but because you have to see something. No lives, no countdown, no way to fail a level. Only "not yet". Lift your finger any time; the board waits exactly where you left it. Every rule is drawn on the board. There is no text on it, anywhere. The clock starts at your first touch, not when the level opens. Thinking is free. Three tracks: a few levels to learn the idea, a long stretch to build on it, and a set with portals — where the hard part is working out where to start. There is a free set to try, across both difficulties. One purchase unlocks the rest, and every level added later. No subscription, no ads. No account. No network. No data collected. It works in airplane mode; progress syncs through your own iCloud.