Loved the details, like I really enjoyed the little 'daring' pop-ups and I also noticed the projectile gets smaller as it gets farther away, I love details like that! I felt like I could pretty easily get away with running back and forth and spamming the shoot button so the gameplay got a little repetitive as it went on. The bigger green enemy was a good addition and helps keep gameplay interesting, I just think there needed to be more different enemies.
Great job! (also I really liked the way you displayed the castle health using the bricks :])