Return of the Dark Sorcerer

Expert and Insane, as well as Hard over Normal, the monster stats are obviously increased, and the jump from Hard to Expert the boss AI scripts become tougher as well, mostly just with stronger attacks here and there in some way, not like totally new scripts. Well, actually the Czar Dragon replacement fought much later does have a new script. With the increase in difficulties, more Gil and more exp is given out in the same kind of way that Diablo (pc game) does for instance. BUT, the characters level curves are also increased, meaning it takes more exp for a character to gain a level. I'm not even sure if this basically balances it back to normal or if the characters level up faster or slower... those things I just never really looked into.

Insane is really meant for the New Game + because it is ridiculous without having nice gear and spells etc., yet some brave souls have attempted it from a new game and have managed to make it playable for some time, somehow. And that's why it's called 'insane' lol. It can be a bit of fun to try to get as far as you can get though.

There is no new/additional party members but there is a couple items to find that can grant you a 'guest character'. You just use the item and it makes the character join the current party if there's room.