Level-Up Trick
When you first start the game, you'll be on a small circle with a building to your left and right and a person above you. Avoid all the roaming monsters on the map, and go down and to the right. You'll see a canyon with a priestlike figure standing in front. He will warn you about the Canyon Beast. Go inside anyway, and get through the small combat zone.
The trick is that the Canyon Beast gives you experience every time you hit it; you don't have to kill it to earn experience points. Whack away at it until it is almost dead, and then leave the screen the way you entered. You'll exit into the world map, but the Canyon Beast will be at full health when you return. Continue wailing on the beast, leaving and letting its health restore until you reach the maximum level. That should take only a matter of minutes.
Magic Tips
The game includes four hidden images. Each image will give you a new spell, and having all of the available spells makes beating the game much easier. The Attack Wizard is in the house just to the right of the starting area. Defeating the Island Beast is necessary before meeting the Shield Wizard. Go across the sea from the Island Beast, and find the blacksmith, who will give you an ax. Return to the forest near the starting area, and chop down at least one-half of the trees. Visit the house at the top right of the forest, and the Shield Wizard will give you the armor spell.
The Life Witch is in the forest in which you chopped down trees; she is in a tree with a bird near the top left of the woods. The Fire Wizard is inside the final dungeon; get to the second floor, take every right turn and follow the hallways to a large torch and the final spell.
Experience Guide
Focusing on enemies worth the most experience is wise use of your leveling-up time. The Blip Blops are worth three points, the Cheshire's are worth six and the Bleaks are worth eight points. The Bridge Weblies are worth 10 points, the Helmetoids are worth 25, the Tower Weblies are worth 35 and the T.O.U.S. are worth 75 points.
Miiscellaneous Tips
Earning as much experience as possible is key. Take each opportunity to fight. Don't forget about your spells. Magic is one of the most useful tools in the game and can make playing much easier. Take some time to explore that game, too.