My first attempt at guns/projectiles.  Press the "Equip" button to select a gun. action/punch to shoot. The Cracker Launcher aims toward your mouse cursor, whereas the Blaster just shoots straight. The fireworks will explode on impact with sounds and a flash of light. You can shoot goombas and give damage in the battle arenas.

I'm still considering how best to handle the gun animations... should it be
1) part of your sprite (you draw all the frames twice, one with a gun and one without)
2) a seperate sprite overlaid on top (like the cracker-launcher)
3) don't do anything (projectile just comes out of your main attack, like the blaster)