Objects are in all levels in city siege 1 and 2, here are some types:
The ground in the city siege games is an indestructible thick object which is always needed.
Thick objects are destroyable things used for walls, floor, and cover, if being hit by falling thick objects the unit will lose health.
Thin objects are destroyable things used for walls, doors, windows, and hiding things.
Explosive objects are explosive items that can be blown up with bullets, falling, or other explosions, these objects are thin objects except the spy´s time bomb, or bombers time bomb, the other objects are: oil barrels and gas barrels.
Props are destroyable objects such as signs, cars, bikes, and sandbags (spiked or not spiked). Some Props can have civilians and baddies on it, including your units.