Like this game's take on a classic idea! Took me a little while to figure out how to actually build towers, since that wasn't covered in your How To very clearly, but I liked the gameplay once I knew how.
The art style was neat, and I laughed when I caught a glimpse of a death animation. Though I completely forgot to switch back and forth for a long time, I was still able to survive with towers focused in Heaven.
Then it told me I'd won and could go to the next level, but clicking the button did nothing. I just assumed that was a "ran out of time to finish" thing and left it there, but neat game!