I'm finding myself playing this game over and over because of how well the firing and hits mix with the music. It ends up creating beats as you play, mixing up the sound of it. Very pleasing to listen to and encourages me to keep playing so I can listen. Not to mention how the charged shot is really satisfying to fire. I would say the only thing that has me as odd is that the planes generate low when the hills are high, causing some to "crash" into the hills.