Bridges is a one-player logic puzzle. The numbered circles are islands. Your goal is to connect every island into one continuous network.
Select one island, then select a reachable island in the same row or column. If Show Possible Moves is checked, legal targets are highlighted; turn it off to solve without connection hints. Repeating the same pair cycles from one bridge to two bridges and then removes the connection. Green islands already have their exact required bridge count.
On prevents you from adding more bridges to an island than its number allows. Off allows overfilling, so you must notice and correct that mistake yourself. Bridges are still never allowed to cross, even when Smart Block is off.
Do not solve islands only by their individual numbers. The final connectivity rule matters too: a locally complete group is still wrong if it becomes separated from the rest of the puzzle.