Crystalux. New Discovery comes from Dmitriy Vasin. The object is to move the hexagons around to form a closed loop or loops.  I must confess that I almost gave up after doing a few levels because it seemed too easy. However, the patterns formed at the end of each level are quite nice. Think Celtic Knots nice.  The reward at the end: the gems glow.

 There are 317 levels.  I've done 60 of the Basic Levels and 17 of the Advanced Levels. None of the Expert Levels yet.  I must admit, I'm stuck - for now. Crystallux is not addictive. It's actually the opposite: just plain enjoyable. https://itunes.apple.com/app/crystalux.-new-discovery/id996508262
https://icecatgames.com/lands/crystalux/index.html

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