Very cute game.
I did not have any sound or music, not sure if that's intentional or not. I felt as if there were a lack of feedback (probably due to no sound) to me as a player of what my towers did, and the strategy part typically in a tower defense gets a bit omitted since the tower type is random.
Perhaps a way to know what the next random tower will be, before placing it, would help with that.
With sound and music, I think the experience would improve alot.
I tried a couple of times and I found it quite difficult.