Dots Connect D

Anyone who has played a flow puzzle will recognise the shape of this one immediately: coloured points sit on a grid, and pipe has to run between them until no square is left bare. The rules behind it are laid out in the rules written for a first game.

igroutka.ru names Flow Free directly as the reference and claims a purpose-built environment and reworked play on top of it. The stated objective is precise — connect the points in the order given and fill the board with pipes — which is stricter than simply linking each pair, because a route that solves one colour but orphans an empty cell is not a solution. From the same group, there is also Merge Mahjong.

The 900 by 600 grid gives enough room that the early boards solve themselves. Later ones turn on a single cell in a corner: if one square would be left stranded, the pipe reaching it has to take the long way round, and that detour usually forces every other colour to move. One more board from the same group is Lappa Connect.

1. Look at the coloured points scattered across the grid.
2. Drag from a point to its partner to lay pipe between them.
3. Take the points in the order the board sets out.
4. Keep going until every square on the board is filled with pipe.

• Fill, do not just link — a Dots Connect D board is only solved when no empty cell is left anywhere.
• Corners first — an orphaned corner square is the usual reason a nearly finished grid fails.
• Take the long way — the shortest route between two points is rarely the one that fills the board.
• Restart a colour early — a route laid in the wrong order blocks the ones that follow.