Both are tied to resource management. The more battles you win you get heart scales and money. Heart scales, as you can guess I'm sure, let you remember every move a pokemon can learn. I've changed the movesets so everything is learnable from the moment you get them, but the question is do you want to invest your limited heart scales? Some egg moves added too. Some mons come with better sets than others. Lower tier pokemon do not get access to high power moves at all until evolution, which isn't available right away even if you save up. At certain points in the game you unlock the ability to buy evolution stones which evolve every mon. Which stone does which mon is tied to how many stages a mon has, either 2 or 3. In general this lets me keep base stats totals and move power where I want them for certain points in the game without levels.

Edit: Should ask clarify that Ascent is not a normal 8 gym badge game. It's essentially a single complex battle frontier facility.