So...this one idea, how about making all of the sonic bosses from 1,2,3, and Knuckles much more harder? Changing the way each boss battles you, etc.
Anyone noticed how unbalanced the bonus dungeons are in FF1 for PSP? I think the normal enemies need a re-balance because when you do the first bonus dungeon at a later date you'll end up being too powerful..but if you do it as soon as you see it..you'll get wiped to the floor by the bosses, but the enemies give you a false sense of security thinking this dungeon is easy.
The enemies and bosses are way too unbalanced as I believe the enemies should be just as much of a threat as the bonus bosses.
FF2 bonus dungeons have the same issue.