I really love the game concept and I had a lot of fun playing through to the end! A good variety of levels and some nice quality-of-life options. Just as a suggestion, maybe it would be nice to have a visual indicator that a level is complete, in addition to the sound? It might be cool to also have a couple more sounds for things like restarting or pushing a piece!

I agree with the discussion about making the pieces more visually distinct—for me it was mostly the black pieces that were hard to identify, I wonder if one solution could be to make some of the details on the black pieces light-coloured so they're more visible (e.g. the cross on the rook)?

I enjoyed the graphics overall though, and some of the piece designs look really good (the knight was my favourite)! It was a great idea to have a halo to identify the kings.