There are a lot of amazing level packs and total conversions out there, but for the most part this thread will be focused on cosmetic or gameplay mods. The core game will remain the same, just with some kind of added twist. Feel free to make suggestions, if you know any good ones. So without further ado...
Weekly Mario Mod #1 (9/29/18)
Frog Suit Challenge
(Super Mario Bros. 3)
Author: ssjtroly

Remember the Frog Suit from SMB3? Remember how awkward it made movement, and how it was only situationally useful? Wouldn't it be super fun to play the entire game with it?
Well, with this mod, you can! The romhack forces you to play the entire game as Frog Mario. Collecting other powerups does nothing but give you points, and if you take any damage whatsoever, you die immediately. Thus the added challenge comes not only from maneuvering in the unwieldy Frog Suit, but having to do a no-damage run on top of it. Apart from a few necessary changes to certain stages that would otherwise be unbeatable as Frog Mario, the levels are exactly the same. Are you a bad enough dude to make it through all eight worlds as a frog?
Gameplay Video
Download Link