I wanted to quickly chime in because I looked at differences between the 3 difficulties when making my Aladdin guide. Please find the differences below:

Practice Start with 5 lives Start with 15 apples Heart heals 3

Enemies Palace Guard (Scimitar) and Palace Guard (Pole) take 1 scimitar hit

Cave of Wonders No fish No boss skip

Inside the Lamp Genie hands always platform

Sultan's Palace No fish

Normal Start with 3 lives Start with 10 apples Heart heals 2

Enemies Palace Guard (Scimitar) and Palace Guard (Pole) take 2 scimitar hits

Cave of Wonders Fish enemies present No boss skip

Inside the Lamp Genie hands alternate sizes

Sultan's Palace Fish enemies present

Difficult Start with 2 lives Start with 5 apples Heart heals 1

Enemies Palace Guard (Scimitar) and Palace Guard (Pole) take 2 scimitar hits

Cave of Wonders Fish enemies present Boss skip present

Inside the Lamp Genie hands alternate sizes

Sultan's Palace Fish enemies present

Commenter Notes The difference in enemy HP between Practice and Normal/Difficult is significant given the prevalence of Palace Guard (Scimitar) and Palace Guard (Pole) throughout game. Both appear in 6/10 stages. The Fish in the Cave of Wonders is insignificant to increased challenge or time The Shiva Monkey boss skip is a large time save for those on Difficult setting The Genie hand in Inside the Lamp impacts 5 jumps and the cumulative time difference is significant on Practice vs Normal/Difficult The Fish can deal additional damage and kill momentum in Sultan's Palace in Normal/Difficult Additional run categories are a potential sign of a healthy, growing community

After switching from Normal to Practice recently, without learning new tech, I did shave off close to 40 seconds but there are also many factors there so I wouldn't reconsider my case beyond a single anecdote. Personally, I'm fine with whatever decision and I'll continue running this game until I reach my time goal.