Known in Japan as "Super Mario Bros. 2," "Super Mario Bros.: The Lost Levels" (which I'll just refer to as "The Lost Levels" from here on out), didn't reach our shores for a few more years.
Once we did get the game, we found that it was still a fun adventure starring everyone's favorite plumber, Mario. We also found that it added new features, such as the Poison Mushroom, and Luigi's first instance of character development (better jump, worse traction).
That said, we also learned that the game was incredibly difficult (even more so than the original) and that it didn't really change a whole lot, feeling more like an expansion pack than a full-blown sequel.
All in all, while some may not enjoy it, "The Lost Levels" is a good Mario game that, while not as revolutionary or groundbreaking as its predecessor, is still an admittedly fun ride...so long as you don't tear your hair out from it.
Final rating: 7 out of 10 "Good"