Mario 2 the future
yeah yeah yeah everyone knows this wasn't a mario game at first SHUT UP MATPAT GET OUT OF MY HEAD
Introduces to the mario series groundbreaking new mechanics like scrolling the screen up, down, or to the left. You still gotta jump on baddies heads but now you can pick em up and throw em. You can also tell mario to go fuck himself and play through the entire game as luigi or blue toad (my beloved). Some extremely interesting mechanics involving a magic potion item you find to then enter a dark world where you can find mushrooms to increase your healthbar or collect coins to use for a one up slot machine between levels, or even warp to much later levels. Luigi floating on an egg over the sea.