Off the top of my head;

the Rebels hid in a giant ice fortress, supposed to be an ancient abandoned castle of some kind
A lot more of the Hoth sequences focused on the Wampa attacks on the base
after leaving Hoth, they went to find Han’s stepfather, a head smuggler who sells them out instead of Lando
Yoda is called Minch Yoda
Luke trains with the ghosts of Obi-Wan and his father (not Vader) and Minch Yoda on Dagobah
Vader is not Luke’s father
In a different draft, Lando was a clone left over from the Clone Wars

These are all half baked memories and I’m unsure how accurate they are