The guide book is important
You won't get far however without the bundled guide book, containing everything you need to know about the caves, dungeons, magic spells, potions, enemies and boss creatures as well as maps, hints and tricks. Without the complete guide book you can still make it to the end of the game but it will be a lot harder if you never played the game in the past.
You need to know a lot of English
Something else that everyone attempting to play the game should know about is that you need to know a lot of English beforehand if it's not your native tongue. As you play the game, you pick up new words all the time but if your English is bad you probably won't get very far. It's one of the few games where you need to actually know the menus in and out and what to use in a certain situation. That said, once you know the game it's easily something you get addicted to playing for hours. Time flies!