A lot of level design in this game is very mundane, uninteresting, and forgettable (yes I just used three synonymous adjectives to enhance my point). Regardless it's not a terrible experience. If I didn't know better I would say that this game feels like it was laying the foundation for future Mario games by being fundamentally different than the first in a lot of ways, such as throwing stuff to deal damage or kill enemies. But for some reason, they went straight to the og format in the sequel and for pretty much every 2D Mario afterward. As I said, I think SMB2 is pretty forgettable in many aspects, and even though we only got this style of 2D Mario once, I'm glad they just stuck to the original style.