This is a Masyu puzzle.
Difficulty: trivial
Theme: Diagonal... Symmetry?!
Theme: Diagonal... Symmetry?!
Alright, so I took my Shindanmaker result a little too literally with "must have one line of symmetry". But it never said the line of symmetry had to go through the centre!
An alternate theme name I could have gone with is "Mostly-White Spade". But I think this current theme stands out best. :P