First of all, let me tell you what I like about this image - I love the idea - I also like the background, it compliments the image nicely. I like the fresh angle you tried to capture - adds to the title.
What you could've done differently - The blue colour. If it was me, I would've done the shot in B&W and then take it to negative. The knight in the front is a bit distracting. It draws the eye away from the king. The foot of the knight is also cropped away (part of it).
Maybe try to have the tild in such a way that it goes from the top left corner (which you got) to the bottom right corner. This will compliment the black vs white idea nicely (two halves).
The edge (borders) of the chess board is also visible - bit distracting on right.
Other than that - nicely done. Cool idea and good execution. I see it is your highest challenge result and you also have one favourite. Good Work.