Complete ROM hack of Super Mario Bros. 3 created by DahrkDaiz, available here. Among the things changed from the original game:
- The levels and World maps, completely new from the ground up (except for the occasional Nostalgia Level).
- A central "hub" where all seven Worlds are freely accessible. The player will always resume their game here.
- Several brand-new power-ups, along with a version of the "spare box" from Super Mario World.
- An "improved" Fire Flower, which now gives Mario a higher jump and fireballs that go in a straight line.
- Many of the graphics have been re-done or replaced, and the weather changes randomly every time you enter a level.
- Infinite lives; coins are now used to buy items.
- A functional "battery" save; the game can be properly played without using save states.
- Getting to World 8 now requires a Key to be found in each of the first seven Worlds, with Princess Toadstool/Peach giving hints upon beating each World.
- Warp Whistles now lead to a bonus area that is unique in each World.
- Nintendo Hard difficulty, but also infinite lives and no Platform Hell design for the most part. Also, if you're really stuck, the Fire Flower or Wand power-ups will let you skip through most of the hard stuff.
- And most importantly of all: Kuribo's Shoe is playable in every level, and can be tucked away in Hammerspace.
So basically everything except the music, the basic concepts, and Mario.
DahrkDaiz is working on a sequel/Spiritual Successor, called Koopa Kingdom Escape.
This game provides examples of:
- All the Worlds Are a Stage: The final world of the game has seven levels themed around the previous seven worlds before the final battle.
- Conspicuously Light Patch: The weather effects don't work on Invisible Blocks.
- Dual Boss: Some levels end in two Boom-Booms, or even three. One of the Desert Dares has four.
- Easy Level Trick: One of the hardest Desert Dares involves staying alive for a set amount of time against a bomb-throwing Warkitu. To survive, you'll need to do some serious running and jumping around to avoid the bombs, or you could simply not move at all, and watch in disbelief as all the bombs fail to make their target.
- Final Exam Finale: The final world contains levels similar to those of the previous world, with a Bowser fight at the end of each.
- Hoist by His Own Petard: The Lakitus can be killed by their own bombs.
- Invisible Monsters: Boos now turn invisible when you look at them (which still stops them in their tracks). Spot checking (by looking the other away once in a while) in fortresses is recommended.
- Interchangeable Antimatter Keys: There is one hidden in each of the first seven worlds, and all must be obtained to unlock the final world.
- Kaizo Trap: If you're fighting multiple Boom-Booms, it's a bad idea to pick up the mushroom they drop while there is still a Boom-Boom left, because you're vulnerable but motionless while the victory music plays. If you're not powered up and/or the surviving Boom-Booms aren't of the flying variety, you'll probably get killed.
- Mini-Boss: Get ready to see Boom-Boom waiting for you at the end of every normal level, except in Desert Dares.
- Minigame Game: World 7, "Desert Dares". Each level is just one screen, with a catch — you either have to make a tricky jump, collect all the coins in time, or survive for a certain amount of time.
- Self-Imposed Challenge: Like the official games, try getting through with minimal use of the power suits.
- Slippy-Slidey Ice World: Lakitu Glacier plays this straight. Because "snowing" is one of the potential weather effects chosen at random, any level can become this (but the weather will randomize after each try).
- The Spiny: A lot of enemies, such as the big Hammer Bros., have spikes added on. Fortunately, there are a few powerups that let you stomp on them still.