Thank you for the great feedback :) I guess when you spend so much time playing it you forget it's actually quite difficult to start off lol. I love the idea of adding the points to the shop and resetting, and increasing the difficulty. I was planning to make it so different patterns appeared in the grid to increase mouse travel and spice things up (I also wanted to make different sized blocks). I also agree on the fade out effect, I should probably make the block flash and shade it to indicate it's no longer in use.
Thanks again!!