Not bad
I did enjoy playing this game and my hands are now quite tired. I didn't find this game to be very challenging, but quite tedious. All you really need to do to win is get the four towers and upgrade them completely. After that just keep spamming A, and S. Spin the crosshair around the castle why you spam and it will send so many arrows in every direction, enemies don't stand a chance.
I would have liked to be able to place my towers and have more upgrades overall. The sound effects need some work as it got on my nerves. I think the arrow rate should be lowered and the enemies should be able to attack the towers. It is a good start, but still needs some tinkering with.