Mario - Our hero, on a quest to save the lovely Pauline.
Pauline - The damsel in distress, awaiting Mario.
Donkey Kong - Big 'n Bad. He trys to stop Mario from rescuing Pauline.
Barrel - Donkey Kong tosses these at Mario in an attempt to thwart Pauline's rescuer.
Fireball - These will chase Mario around and try to fry him before he rescue's Pauline.
Jack - These bounce from the direction of Donkey Kong, and can make Mario's day miserable.