Kept walking to the end of the level and found some sort of horn. I'm assuming you're supposed to shoot the depressed guys with that? Stopped playing after that.
I like the music though. Very serene. Did you compose this piece yourself?
Yes, you find a cannon (not horn) at the end of the first map. After that you can shoot enemies with that cannon in the next levels. First map is just for learning the game.
Musics are from Jamendo, they are free to use for non commercial purposes.