Very well made, and very fun. A few minor things did jump out. When the comet bounces at a corner, the following direction seems impossible to predict, sometimes causing me to lose a life. There was also the time that the collapsing tower interacted with the comet at the time it teleported, causing it to appear behind the portal and immediately going off the side of the screen. Also, the button sound effects are way too loud, especially compared to the music.