DD6A-646F Start with 1 life instead of 3
D06A-646F Start with 5 lives
DB6A-646F Start with 10 lives
D36A-646F Start with 15 lives
F66A-646F Start with 25 lives
7F6A-646F Start with 50 lives
146A-646F Start with 99 lives
C2B3-D46D Infinite lives
DD6A-67AF Start with 1 credit
D96A-67AF Start with 6 credits
C2CD-0F0D Infinite credits 
CBBE-DF94 + FDBE-DFB4 Fruit restores full energy

On the next two codes, don't use the game's super jump feature. 
The codes don't work for the skateboard
798C-DF0D Super jump
408C-DF0D Mega-jump
79C0-A7DD + 79C6-A4DD Don't lose all weapon power when you die--may give you 
unusual weapons
D766-0FD7 Start in area 1, stage 2
D966-0FD7 Start in area 1 bonus round
D566-0FD7 Start in area 1, stage 3
DC66-0FD7 Start in area 2, stage 1
DA66-0FD7 Start in area 2, stage 2
D366-0FD7 Start in area 2 bonus round
FF66-0FD7 Start in area 2, stage 3
F066-0FD7 Start in area 3, stage 1
F666-0FD7 Start in area 3, stage 2
FC66-0FD7 Start in area 3, stage 3
F266-0FD7 Start in area 4, stage 1
FE66-0FD7 Start in area 4, stage 2
4D66-0FD7 Start in area 4 bonus round
4066-0FD7 Start in area 4, stage 3
4566-0FD7 Start in area 5, stage 1
4B66-0FD7 Start in area 5, stage 2
4866-0FD7 Start in area 5, stage 3
4266-0FD7 Start in area 5, bonus round