I have another game.
I don't know a real lot about it, though... I remember playing it at a friends' on the original Gameboy. I believe you controlled a mole(I DO know you controlled him in a Zelda-ish style, if it's about movement. Can't remember any battles >.<). One button also got the mole dude to dig... I think. Yeah, it's fague, but all I remember.
EDIT: Never mind got it. Thanks Wikipedia 
...wait. That sounds like that game with the hamsters in it...uuuhg...
Hamtaro! My sister has it for the GBA, and you can dig and stuff, and that's about it. Maybe they had it for the old game boy or gameboy color?
Unless you're sure it was a mole, then I have no idea.