Same, I don't know how can I use the projectiles to get over the wall. I even tried to change to the second character when the projectile was mid-flight, because the tiles looked cracked, but to no avail.

Looks nice and has good potential. But I wasn't actually able to pass the point where you first get tutorial about shooting projectiles? I guess the wall has to be destroyed, but I couldn't manage it. 

Otherwise, looks good and it's a pretty nice take on the theme.