The last dungeon:
Make sure that you have defeated Cyril and have made it to the final save point in Fienal. Turn back and head out to Fun City. Go to the stadium, and talk to the weird old man by the back. He will say "Do you want me to recover your memories?". Answer "Yes" both times and you will be teleported back to Expel. When you leave Arlia, your trusty Synard will be waiting. Fly over to the unexplored island and enter the Cave of Trials. Beware -- this dungeon has monsters that range in levels from 100 to 300.

Santa's Boots:
After you gain access to the Cave Of Trials, go to Arlia and enter the honeymooner's house. They have a son now, and you can pick pocket the Santa's boots from him. Save the game before attempting this, in case you fail. Note: The Santa's Boots normally cost 20,000,000 FOL.

Higher levels:
Enter a time when starting a new game. You will more likely to surpass level 99 during the game.