Strategically, this puzzle is a combination of range and slitherlink.
Puzzle and Goal
An unsolved puzzle consists of a rectangular grid with numbered clues in some of the cells.
The goal is to draw a single open path that satisfies the clues.
The solved grid must satisfy the following conditions:
Numbered clues represent the number of orthogonal neighbors (including itself) that the number can see; colored cells block sight lines.
All non-colored cells are contained in a Jordan curve (that is, it is a single non-intersecting closed loop).