EX Game Mode
Finish the game once to enable an option that allows the game to be played in a new mode.

Infinite Bullets
When in the NYPD go downstairs and enter the left door. You can find the bullets in the box near the counter. Take the bullets and go out to the New York map. Now return to that room for more bullets. Repeat that as often as you want.

Infinite Medicine:
When in the NYPD go downstairs and enter the left door. You can find the medicine in the box at the top right of the room. Take the medicine and go out to the New York map. Now return to that room for more medicine. Repeat that as often as you want