The caves in Pikmin 3 just seemed like load screens to make to area larger. One thing I didn't like about the bosses in Pikmin 3 was that you had to dedicated a single day just to fight the boss and after it's beaten normally you won't have enough time to get all the items. I know you can go back to get the items, but it just seems like a waste of a day when that is the only item available to get.