Hashiwokakero (Hashi) is a type of logic puzzle published by Nikoli.This is a Hashi implementation.

Hashiwokakero is played on a rectangular grid with no standard size, although the grid itself is not usually drawn. Some cells start out with (usually encircled) numbers from 1 to 8 inclusive; these are the "islands". The rest of the cells are empty.

The goal is to connect all of the islands by drawing a series of bridges between the islands. The bridges must follow certain criteria:[2]

They must begin and end at distinct islands, travelling a straight line in between.
They must not cross any other bridges or islands.
They may only run orthogonally (i.e. they may not run diagonally).
At most two bridges connect a pair of islands.
The number of bridges connected to each island must match the number on that island.
The bridges must connect the islands into a single connected group.

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Basic Operations:

Moving the mouse between two islands will show a bridge preview. Left-clicking will change the bridge state, cycling between 0, 1, and 2.
Moving the mouse over an island will display the possible bridges associated with that island.
If a place has two potential bridges, first move the mouse over the island, then move it to the conflicting bridge location. This will show the bridges associated with that island.

Auto-Completion:

Move the mouse over an island and hold the left mouse button for 2 seconds to instantly complete the bridges related to that island. This action consumes a score multiplier. If the score multiplier is insufficient, this command cannot be executed.
This feature is just a hint for beginners, and as players' skills improve, all puzzles can be solved through logical reasoning.

Locking an Island:

If the number of bridges around an island matches the island’s number, you can attempt to lock the island. If locking fails, it indicates an incorrect solution, and a score multiplier will be deducted. If locking is successful, you will gain points. Once locked, the island and its related bridges can no longer be modified.
This puzzle has a unique solution. Therefore, if you cannot lock an island, it implies that the solution is incorrect.

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The game contains a total of 300+N challenging levels for 6 board sizes. There are a variety of color themes to choose from.

The game also includes a scoring system and leaderboard feature, allowing players to compete against players from around the world.

If you have any suggestions to make the game better, you can tell me in the steam community.