The Solo Challenge
For an even sicker challenge playing FF1, try to beat the game using just one party member. To do this, start a new game, choose the class of your character, and name him or her. The rest should be all the same class, and named 'Dead'. As the game begins, go into Corneria and buy weapons and armor for your one character, and equip them. Then, proceed out into the woods surrounding Corneria and execute the three Dead characters.
The challenge, obviously, is to beat the game then without reviving anyone. Of course, you could revive the three dead characters at any time, but what's the point if you're just going to cheat? Anyway, your choice of character class for your solo hero is very important. It's easiest (although it's hardly easy) with a Red mage, as they are able to use white magic, black magic, and still be a relatively powerful hand-to-hand fighter. Arguably the most difficult class is the white mage, due to their extreme lack of offensive capabilities, or the thief, due to their inability to heal without potions.
I have never personally done this, nor have I even really tried. I can assure you, though, that it would be very, very hard.