From Rockstar Games:
This download contains sample levels for users who wish to create their own mods for Max Payne 2. They should be used in conjunction with the official Max Payne 2 mod tools. There are two files included in this download. Physical_objects.lv2 is an extensive compilation of dynamic objects from the game, ranging from chairs and desks to explosive ammoboxes and watercoolers. DMW_Manor_Frontyard.lv2 is a source level file for the Manor Front Yard Dead Man Walking level.