The visuals are really simple and nice, with a good color scheme. The game plays smoothly, and it's a wonder to play, with satisfying screen shakes and audio queues.
The lack of music is a bit off-putting, but it is not much. The fact that the turrets only aim at 45 degree intervals can make aiming mildly annoying, and solutions to levels feel more like guess-and-check rather than finding a good solution. If there were a little bit more options to shoot the turrets, or have more variety in what combining turrets do, this would be really good. Good job though!