Harvest Moon Cheat Codes for Gameboy

Cool Cow

When you get your first cow start it's name with a heart symbol
and it will give good milk and grow up fast.

Infinite Egg
Wait until one of your chickens lays an egg directly above the
shipping box. Water the egg and it will turn into a block. Now
pick up the "egg", and you will have infinite eggs, and lots of
money!

The Name Game
Capitalize the first letter of your name to grow eggplants and
carrots. Leave the first letter of your name lowercase to grow
peanuts and broccoli. To grow all of the above, make the first
letter of your name begin with a symbol, such as a heart.