Lokki: Train Puzzle for Kids

A hundred and fifty timing puzzles for ages 4–10. Two rules, no reading, no timer, no losing. The first twenty levels are free.

Lokki is a quiet puzzle game about trains — and about the one thing every railway has to solve: not being in the same place at the same time.

Trains run in loops on a shunting yard. There are gaps in the track. Your child picks a piece and taps a gap, and the train sets off. Nothing to read, nothing to press to start: the yard is already running.

TWO RULES, NO READING • A train goes where the track goes, and never reverses. • Two trains cannot be on the same piece — so if they both arrive at once, both stop.

That second rule is the whole game. There is no referee, no "the right one goes first" — a rule a child cannot see on screen is a rule we did not write. When two trains meet, they simply stand there, and your child moves a piece.

THREE PIECES Track — crossed in one turn. Loop — a curly piece, crossed in two. This is how you slow a train down without a speed setting anywhere in the game. Passing pocket — one piece where two trains fit side by side.

THREE WORLDS Track (ages 4–6) — close the gaps and the train runs. Continuity, direction, cause and effect. Meeting (ages 6–7) — two trains, one junction. Adding a loop delays one train by a turn, and the jam is gone. Simultaneity, waiting, "not at the same time". Lap (ages 8–10) — two separate loops that cross. A lap of 14 and a lap of 6 meet at the crossing every 42 turns; make one lap 15 and they never meet again. Common multiples, before multiplication.

FEWEST PIECES Finishing is worth one star. Three stars go to the smallest solution. Every level's minimum is computed by a solver, never guessed — so the goal is always reachable and always honest.

NO LOSING No timer, no failure screen, no punishment, no sound for a mistake. A jam is not a loss: it is what railways do when two trains want the same rail, and it is fixed by lifting one piece.

MADE FOR CHILDREN, HONESTLY • No ads. Ever. • No data collected. No analytics, no tracking, no accounts, no network code at all. • No permissions requested — no camera, microphone, location or notifications. • Works offline. • One purchase unlocks everything, behind a parental gate. No subscription. • Four languages: English, Türkçe, Deutsch, Español.

The first twenty levels are free — a complete world, not a cut-off demo.