Score
0
Time
90s
Best
—
Edge-clue logic puzzle — place buildings 1–4 so each row and column has no repeats, and the numbers around the grid match how many buildings you can see. Solve as many as you can in 90 seconds.
Tap a cell to raise its building height; tap again to cycle 1, 2, 3, 4, then empty.
Every row and every column must contain each height exactly once — like a tiny Sudoku.
The number on an edge is how many buildings are visible looking inward from that side. A taller building hides every shorter one behind it, so a clue of 1 means the tallest building is right at the edge, and a clue of 4 means the heights climb 1-2-3-4 in order.
A clue turns green when its line is filled correctly and red when it is wrong. Solve the grid to score, and a fresh puzzle appears instantly. Rack up as many as you can before time runs out.
Start from the extreme clues, because they remove all guesswork. A clue of 4 on a 4-wide grid forces the only ascending order 1-2-3-4, and a clue of 1 forces the tallest building 4 right against that edge. Filling those lines first hands you a scaffold the rest of the grid must agree with.
Clues of 2 and 3 are softer but still powerful once you combine them with Sudoku logic. A clue of 2 means the tallest building is somewhere behind exactly one shorter one, which usually rules out the tallest height from the first cell. Treat each clue as a filter on which heights can sit in the first few cells, then let the no-repeats rule finish the line.
Work the pairs of opposite clues together. A column seen as 1 from the top and something larger from the bottom pins the 4 to the top cell immediately, and the bottom clue then tells you how the remaining three stack. Cross-referencing a top clue with its matching bottom clue often cracks a whole column in one step.
For the timed mode, speed comes from pattern recognition, not raw calculation. After a few rounds your eye will jump straight to the 1s and 4s, place those, and let the rest fall out. Do not chase a stubborn cell — fill everything you are certain of first, and the contradictions will usually point to the answer.