I have a lot of nostalgia tied to this, especially since I played it when I was 9 and play it every so often. I really loved how they updated the game over the years, one example being how the firesaur and treezard monsters where updated. It's not very innovative when it comes to updating the new event monsters (idk what they were called but i think u get what I mean) and i liked the little snippets of story linked between some of the monsters.
I think this is pretty fire for a mobile game, coming from someone who isn't a hardcore gamer and mostly likes mobile games :P