Moon or Sun is a puzzle type originally found in Puzzle Communication Nikoli volume 154. Here is a six-puzzle exploration of this type.
Rules
1. Create a single loop that passes through some cells without branching, intersecting, or moving diagonally.
2. Each bold-outlined region can be entered and exited only once.
3. Bold outlined regions contain moons or suns. In each region, the path must either pass through all of the moons and pass through none of the suns or pass through all of the suns and pass through none of the moons.
4. The path must pass through at least one symbol in each bold-outlined region.
5. The regions the path passes through must alternate between suns and moons.
Example
Puzzles
All of the puzzles can be found organized in this printable PDF, or in the images below.
PDF Moon or Sun
01. Easy
02. Medium
03. Medium
04. Hard
05. Hard
This puzzle, has been corrected…again.
06. Expert
Paramesis Puzzle Blog 
Number 5 appears to have a slight ambiguity in the large bottom region.
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Thanks. I made an error copying the puzzle from my notebook, which has been corrected.
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Another ambiguity in number 5, if I’m not mistaken: R3C9 could connect directly to R3C10, or via row 5.
I’m really enjoying your puzzles, thank you! The upcoming LMI contest finally got me to put in the time, well worth it.
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You are correct. I added another sun to fix the ambiguity.
I’m glad you’ve been enjoying my puzzles. Sadly I won’t have much time for puzzling in the next few months, but when I do, I’ll definitely try out some of the very interesting puzzles on your blog.
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