It would be cool if *some* parts of the TARDIS had 2 models: broken and non-broken. Like in "Let's Kill Hitler" when River shot the console, deadly gasses came out. Is it possible that if somebody were to shoot the TARDIS in game, a gass particle would appear and possibly players taking damage. It's just an idea starter. It could be neat. Also if the TARDIS is damaged it could affect flight/dematerialisation/controls etc.

Image1[blogitoutb.com]

Image2[4.bp.blogspot.com]