FFT is one of those rare games I've played more than five times. It's moderately difficult to win the game the first time, but it's very challenging to get everything the game has to offer: rare weapons and armor, getting Ultima for Ramza, getting Zodiac (for every human character!), winning every Proposition reward, breeding rare monsters. And I never even tried catching weapons in Deep Dungeon or the Level Up/Down trick.

So there's enough richness in the game that you'll want to replay it anyway.