I guess the cursor stays in the square where you started the swap instead of the one you finished at even though it doesn't look like it, which is a bit confusing. Also it is not clearly visible if you are holding a piece at the moment or no. The background is a bit overwhelming, but maybe you could make it start slow and make it go faster as you score. There is no way to lose now, so it could use a timer that also speeds up as you go.
Anyways I could see it as a gameboy time killer. I also like the art style