DD65-67DF + 6D65-670F + D965-676F Start with section 1 finished
DF65-67DF + 6D65-670F + D965-676F Start with section 2 finished
D465-67DF + 6D65-670F + D965-676F Start with section 3 finished
D765-67DF + 6D65-670F + D965-676F Start with section 4 finished
D065-67DF + 6D65-670F + D965-676F Start with access to all sections
DF6C-D704 Start with 1 life instead of 3
D46C-D704 Start with 2 lives
D96C-D704 Start with 5 lives
D56C-D704 Start with 7 lives
DB6C-D704 Start with 9 lives
C265-0FA7 Infinite lives
DD6B-D764 Start with 0 custard pies 
D46B-D764 Start with 2 custard pies
D96B-D764 Start with 5 custard pies
D46B-D764 + DF6C-DDA4 Start with 2 superballs instead of 10 custard pies
D96B-D764 + DF6C-DDA4 Start with 5 superballs
DF6C-DDA4 Start with 10 superballs
D43D-67D7 Custard pie bonus worth 2 pies instead of 10
D93D-67D7 Custard pie bonus worth 5 pies

Using the next two codes together will freeze the game on pick-up of superball 
or pie. Switch off effects to unfreeze

D03D-6767 Custard pie bonus same as superball bonus
6D3F-6DA7 + E03F-6FD7 Superball bonus same as custard pie bonus
D43F-6F67 Superball bonus worth 2 balls instead of 5
DC3F-6F67 Superball bonus worth 10 balls
C1E1-D7DD Infinite custard pies
C1E2-D76D Infinite superballs
D53E-0407 Food bonuses restore less strength
F33E-0407 Food bonuses restore more strength
173E-0407 Food bonuses restore Krusty to full strength
D03D-6FD7 Food bonuses also get custard pie bonus
D33D-6FD7 Food bonuses also get superball bonus
3134-6D67 + 6D34-6D07 Doll bonus same as custard pie bonus
ED34-6D67 + 6D34-6D07 Doll bonus same as superball bonus
2F34-6D67 + 6D34-6D07 Doll bonus same as food bonus
8725-0D64 Krusty invincibility
FD3C-D704 Krusty jumps higher
D63C-D704 Krusty jumps much higher