Really nice game, love the cute "boxy" art style and the music is really well suited to contribute to the ambience of the game. If you guys continue to develop the game it would be nice to have a grid overlay, to be easier to identify where you can put towers. Also the tower info seems a little bit misguidind: i started with 75g and the first tower had two numbers indicating 50 and 25, i was not able to identify which one was the price and when i purchased it spend 45g.
Other than that is a pretty nice game, keep it up!!