Walk Anywhere!
This cheat is something I found by pure chance and have never seen printed elsewhere:
First off, you must have either a Mutant M or a Mutant F in your party. When you are in the world with the Dragon Race, enter the dragon race (you can pick any dragon you want, but I prefer the slowest one; it's free.) . You will meet with 1 to 4 bosses, depending on which dragon you choose. The last boss is called a Watcher. SAVE IMMEDIATELY before you fight it. Fight the Watcher until your Mutant receives the skill Teleport (This can take multiple resets to accomplish, but don't give up!!) Teleport anywhere, it doesn't matter, just make sure you're riding the dragon while you do it!! You will end up at your destination riding your dragon (It might not LOOK like a dragon; as a matter of fact it can sometimes look really glitchy, but it won't affect your game. Don't worry.). Now walk around. Bingo!! Ever wanted to cruise on those damn mountains? Now you can! Have fun!!

Sound Test
On the Title screen, simultaneously press Select, B and Start. Change the number by pressing Left/Right, and listen by pressing the A button.