Firefly Beam is probably a Nikoli original.
Puzzle and Goal
An unsolved puzzle consists of a rectangular grid. Some of the grid intersections contain circles with a dot on one side; some of these contain a numbered clue.
The goal is to connect all of the circles into a connected graph.
The solved grid must satisfy the following conditions:
Circles are connected along grid lines starting at a dot and ending at any other side of a different circle.
Numbers, when present, indicate how many turns the connection takes.
Once the puzzle is completed, it must be possible to move from any circle to any other circle along connection lines.