The easiest way to get those extra levels is to go someplace like the base of the tower, trigger the alarm, point your dragon at the wall, throw a rubber band around the B button, and then go watch a movie. You'll automatically blow through every encounter and gain a level every 10 minutes or so. It's totally not necessary for beating the game! I only leveled up to 99 just to see what would happen. :)

How long did it take you to reach level 99? =o