The Lost Levels is a remake of the Japanese version of Super Mario Bros. 2, which was later released in North America as The Lost Levels. Being that 1.6 Mari0 didn't have all the features of the original, it isn't a perfect recreation, and some clever alterations had to be made.
Interestingly, there is no mention of making a port for SE, despite the version including many features that would make a port far more accurate, notably infinite Worlds, Custom Enemies, and Poison Mushrooms.
As Mari0 is based on SMB1, the following objects were omitted:
- Worlds beyond 8 (They were instead split into a separate mappack)
- Poison Mushroom
- Red Piranha Plants
- Ceiling Pirhana Plants
- Wind (replicated with use of Speed Gel)