In Mallcrashers, your goal is to destroy $50000 worth of property. I know destroying store glasses counts towards the goal. Destroying the glass railings seems to count, too.
What else counts towards it?
You can destroy lots of stuff:
Note that trip mines can prove useful in this level: simply plant one in the middle of an area where you want to blast stuff (liquor bottles for instance) and shoot at it.
You can add gas cans to your assets in this mission which can be used to set the gym, clothing stores and a few other places I think on fire.
Another good tactic, and one which will earn you the Steam achievement "Shoot the Glass!", is shooting the upper level windows upstairs. They are just below the skylight, and are panel glazed.
I also tend to shoot out all the black and white shop signs and mall brand signs.
There is a car in the car show room. That counts too as well as a wine store where you can destroy glass bottles. I would like to know how does the gym and clothes stores count towards the total?
Pretty much everything that breaks counts toward your goal, If you place a trip mine in the "Pear Store" that will gain a lot of damage. Also the wine bottles in the liquor store, and the car in the showroom are all great ways to rack up the damage fast.