|I managed to complete all 3 versions of this game. It's okay, but way too trollish. A lot of this game feels like a bad romhack... The extra levels (worlds 9, A, B, C, and D) are especially annoying because they have a lot of windy levels with large gaps, and levels where you have to use mega springs to jump between large gaps, and some really weird blind jumps that require you to hop on turtles at the right time when you can't even see the turtle before the jump.|
The SNES version is the most fair version, because it has the higher bounce height of SMB3, making it much easier to do the turtle jumps. The Famicom version and the GBC version both have the usual SMB1 bounce height.
The GBC version also has wind removed, which is definitely a good thing, but it doesn't have worlds 9-D, and you can only play as Mario in that version. The Famicom version does have worlds 9-D, but they are way harder to unlock than in the SNES version. To unlock world 9 you have to beat the entire game up to 8-4 without using warps. And to unlock worlds A-D you have to beat 8-4 a total of 8 times. In order to really say I've completed this game, I had to do this in order to play the original Famicom version of worlds A-D, which are much harder due to the decreased bounce height.
I never want to play this game again... There's such a thing as good difficulty and bad difficulty, and this game is the latter.