Pixel graphics, 8-bit sound effects and music. What is not to like? Thanks for the music mute though... appreciated.
A great wee puzzle game, very tight and well implemented. I did find the slight pause during movement caused me to 'queue' keypresses initially and I went too far in a direction, but I adjusted and got the hang of it. I wasn't sure what the red and green marker meant, but related to the keypress.
I think a wee bit of feedback when a move attempt fails (sound effect, slight shake or similar) would be a good addition.
I was keen for more to be honest... :) Good work!