Very good level! A 5 from me.
If you categorise hard levels by how many have solved them, this is on a third place I think. I have one level solved by one person and another solved by two persons.
Not sure how to comment on this one as it has some very good and bad aspects to it. The concept is brilliant in my opinion and the design is great except for a couple small changes I would suggest. First, you might want to double the size of the sun in the center. The difficulty would still be high but you want the level to be possible and fun to attempt for more players. Perhaps a smidgeon bigger for the lower sun too. Second, I would suggest lowering your "anti-cheating" switch at the bottom of the lower sun so that the edge of it barely rises above the lower border. This would still accomplish your intended security measures against node spamming but not set it off otherwise. Definitely 5 star potential with a few tweaks.
If you categorise hard levels by how many have solved them, this is on a third place I think. I have one level solved by one person and another solved by two persons.