Castlevania: Circle of the Moon Tips
To constantly gain levels just go to one of the poison worm things on the roof of the caves. Get under the worms. Tape the down button down so you are in a kneel. Then tape the B button down so your whip is constantly turning. Then You just have to leave you gameboy on and you will get constant Exp. If you have a Gameboy advanced SP then just plug it in with the adapter so that the batteries dont run out. Leave it for a couple hours and see how many levels youve gained.