Beautiful, fun, and challenging in places.
NightSky has relatively simple controls (Left, Right, and two action keys) but uses them well to give a wide variety of puzzles. The levels can be challenging to figure out, and even once you've discovered the solution to a puzzle, implementing that solution can be a little frustrating. Only a few levels get to the point of being frustrating, and for the most part the game had a sort of meditative quality to it.
The artwork is beautiful and the soundtrack complements the art and the gameplay nicely. One major flaw of the game is that higher resolution settings will cause the game to take up only a portion of the screen. On my 1360x768 TV, I would estimate that 50% of the screen was unused black space.
The game lasted me about two and a half hours, and I could see myself going back to try out the harder difficulty level.
