Really cool game! Keep working on it. A few things: 1) the WASD controls on the keyboard are for the rightmost block, which is a little confusing at first since my hand is on the opposite side from my block. 2) can you add a button from the control window back to the menu? and what about a button from the game back to the menu? 3) lastly, i think the blue block is stronger than the green one for some reason, so it's a little unbalanced.
Those are just small things though, I'm having a lot of fun playing! :)