DB66-4DD4 Start with 10 lives
D166-4DD4 Start with 7 lives
DD66-4DD4 Start with 1 life
82AA-CF07 Infinite lives
DD30-1FA7 Infinite weapons
DB6B-4F04 Start with 9 first aid kits instead of 1
DD6B-4DA4 Start with 50 shots in squirtgun
DD6B-4D64 Start with 100 shots in squirtgun
D96B-4DA4 Start with 550 shots in squirtgun
DB6B-4DA4 Start with 950 shots in squirtgun

For the next 12 codes, press B or Y to get the selected item. 
Start with first aid kit
266B-4704 Start with soda pop cans Instead of squirtguns
216B-4704 Start with bazookas
2C6B-4704 Start with tomatoes
A36B-4704 Start with fire extinguishers
2A6B-4704 Start with ice pops
236B-4704 Start with "peppers"
2D6B-4704 Start with martian bubble guns
246B-4704 Start with weed-eaters
206B-4704 Start with ancient artifacts
3D6B-4704 Start with plates
346B-4704 Start with silverware
306B-4704 Start with footballs

For the next seven codes, press B or Y to get the seleted item

D36C-4DD4 Start with speed shoes instead if a first aid kit
FD6C-4DD4 Start with a monster potion
F46C-4DD4 Start with a ghost potion
F06C-4DD4 Start with a random potion
FA6C-4DD4 Start with a pandora's box
F36C-4DD4 Start with a skeleton key
4D6C-4DD4 Start with a decoy
DD39-34D4 Infinite special items--except keys and random potions
DD3F-1DD4 Infinite keys once you have at least one
DBEC-4704 Package of 99 squirtgun shots worth 999
BBE8-44D4 Package of 20 Soda pop cans worth 99
BBE8-4464 Package of 20 tomatoes worth 99
BBE8-4FA4 Package of 5 bazookas worth 999
DBEF-1F04 Each first aid kit worth 9 on pick up
DBED-1FA4 Each key worth 9 on pick up
D965-4464 Start with 1/2 health
D921-1DD4 Continue with 1/2 health
3C20-4D0D Infinite health

For the next two codes, you don't get the bonus for rescuing all victimc. 
If the zombies eat 1 victim, the game is over
DF63-14DF Only 1 victim to rescue per level
BAA1-44A4 Can advance to next level after getting 1 victim

D46E-1D0F Start on level 2
D76E-1D0F Start on level 3
D06E-1D0F Start on level 4
D96E-1D0F Start on level 5
D16E-1D0F Start on level 6
D56E-1D0F Start on level 7
D66E-1D0F Start on level 8
DB6E-1D0F Start on level 9
DC6E-1D0F Start on level 10
D86E-1D0F Start on level 11
DA6E-1D0F Start on level 12
D26E-1D0F Start on level 13
D36E-1D0F Start on level 14
DE6E-1D0F Start on level 15
FD6E-1D0F Start on level 16
FF6E-1D0F Start on level 17
F46E-1D0F Start on level 18
F76E-1D0F Start on level 19
F06E-1D0F Start on level 20
F96E-1D0F Start on level 21
F16E-1D0F Start on level 22
F56E-1D0F Start on level 23
F66E-1D0F Start on level 24
FB6E-1D0F Start on level 25
FC6E-1D0F Start on level 26
F86E-1D0F Start on level 27
FA6E-1D0F Start on level 28
F26E-1D0F Start on level 29
F36E-1D0F Start on level 30
FE6E-1D0F Start on level 31
4D6E-1D0F Start on level 32
4F6E-1D0F Start on level 33
446E-1D0F Start on level 34
476E-1D0F Start on level 35
406E-1D0F Start on level 36
496E-1D0F Start on level 37
416E-1D0F Start on level 38
456E-1D0F Start on level 39
466E-1D0F Start on level 40
4B6E-1D0F Start on level 41
4C6E-1D0F Start on level 42
486E-1D0F Start on level 43
4A6E-1D0F Start on level 44
426E-1D0F Start on level 45
436E-1D0F Start on level 46
4E6E-1D0F Start on level 47
7D6E-1D0F Start on level 48
746E-1D0F Start on bonus level Son of Dr. Tongue
776E-1D0F Start on bonus level Day of the Tentacle
706E-1D0F Start on bonus level Someplace Very Warm
796E-1D0F Start on bonus level Curse of the Pharaohs
716E-1D0F Start on bonus level Mushroom Men
756E-1D0F Start on bonus level Cheerleaders vs the Monsters
7F6E-1D0F Start on credit level Monsters Among Us