Cheat codes:

UNTIMED       Single frame advance with C right.
HEADLINE      View all Newspaper headlines.
NOBUNDLE      Have unlimited papers all levels.
INVINC        Inf Health
JUMBLE        Run into Invisible objects
SCREAM        Everything you hit emits scream
MOON          Jump super high in air
WAKING        Slo motion
RUSH          Turbo mode, clock too.
ALLJUMP       Always have Super Jump Springs
GOFAST        Always have Rocker Boosters
BACKWARD      Papers get thrown backwards
LITTLE        Paperboy is super tiny
MAGOO         Near sighted paperboy, only see short distance if front of you
SUNDAY        HUGE newspapers.
MAXSUBS       Level select
OBVIOUS       Level select.
RANDOM        Random paper tossing.
FRONTS        Throw papers directly in front of character.
SIDES         Throw papers at 90 degree angle.
THUMP         Cartoon sounds
THUNK         Cartoon sounds

Destroying Neptune:
     This is how to beat the spaceship in medium mode.

Regular Alien               1 normal paper
Mini UFO                    1 normal paper
Eyeball Lightning Alien     1 power throw.
King Brain Alien            Around 5 or 6 power throws.
                            Note: You must be on the top level to hurt
                            the King Brain Alien. 

How To Get Extra Papers:
     To  get  the extra papers on boss battles, you just have to press
the  L  and  Z buttons repeatedly while the camera is adjusting, right
before the battle starts.