Some of the other things that have been changed/randomized are the location of TMs, rare candies, and some other items.
That is the reason I have described it as a pretty engaging game. The difficulty level, graphics, and some customization have completely changed in it. You won’t be able to find the Pokemon in the previous locations nor are you able to catch them in the same way as before. In terms of the gameplay, this game starts with the same introduction as the original one but as soon as you move towards completing the missions things will start changing.