It could even be played wit teams each team gets a catapult they set up on top of a 120 meter tall wall made of 10x10x10 blocks ans the catapults fire flaming fireballs that whisper on impact to tell the wall to die but before it does it rezzes 4 chunks that have phisics enabled and are phantom and smoke all the way to to the ground>
I said teams because its a little hard to se where your shot landed unless it hits the wall then you see the wall crunmble and go down but if you miss it could be falling short or going over I've been turning my view up to 96 so i can see the wall but the flaming fireballs disapear just b4 they get there so on impact they rezz a 4x4 lit up clear sphere with a particle explosion that is visible from a distance snapzilla picture link hope thats ok another one tried it in a smaller scale using on impact to decide if it hit but it took all night to destroy a wall tiny size now im thinking it'd be cool if when you took out a wall at the base if the walls above it came down a notch along with the catapult on top might get that figured out soon but if your interested come be montmartre thats where im experimenting with it