I felt a little lost at first, and I definitely think that a sort of tutorial would help to make new players have a better awareness of what's going on. A more cohesive art style would also benefit the visual appeal of your game. However, once I began to understand the mechanics I was impressed by how unique it is. A tower defense game where you get so much direct interaction isn't something you see often. Having your buildings support the interactive mechanic of shooting is a great idea as well. I was also a big fan of the thought and care that went into the menus with their satisfying animations. Overall I think you are really onto something with this game, keep it up!