As you guys already know, World 2 is the beach world and in the original hack it was... quite messy, i started working on this world back in early October 2015 (pretty much 5 years ago) a few days before i was unbanned from SMW and back then i had very little level design knowledge so most of the levels were unfairly difficult so most of the updates to the levels in this world were related to difficulty balancing and other improvements, here are them.
2-3: Moonlit Harbor
This was mostly an alright level and the main updates here is that it now has a bit more focus on the bubble flower power-up, specially because now you can use it to access higher areas that are otherwise unreachable. The music has also been updated
2-4: Flooded Fortress (formerly known as Flooded Cave)
Probably one of my favorite levels from the hack, the main change here is quite obvious as i decided to change it from a cave level where the water randomly lowers and rises to a fortress where you change the level of the water by pressing switches, similar to how it was in the demo version. And now with the newer LM updates, it's a lot easier to make this concept work.
And lastly, i moved the secret exit from 2-5 to this level because it was a pretty good level to hide secrets.
World 2-5: Urchin Reef (f.k.a. Underwater Ways)
One common issue with many of the cave, castle and underwater levels in the original hack is that due to the SMB3 status bar, many of these levels were very cramped, but now that the hack has a better status bar, this issue is fixed. Other than that the level is mostly similar to the original one and it's even better with the frog suit as it makes the gameplay more fast paced and Mario doesn't get affected by the air currents.
And as i said before, there's no more secret exit to be found here.
World 2-6: Dolphin Coast (f.k.a. Dolphin Shore)
This is mostly the same as the old one with no major changes aside from level design improvements.
World 2-7: Stormy Shore (f.k.a. Rainy Beach Ruins)
Most of the changes here were aesthetical changes as it was a fine level but wasn't very appealing to look at with these ugly layer 3 rain effects and a very dull gray-ish palette. The music has also been updated
World 2-A: Haunted Galleon (f.k.a. Blue Switch Ship)
The main change is that this level now has two exits rather than just being the blue switch level, the normal exit now is a shortcut to 2-7 while the other exit is the switch palace. Other than that the level is mostly the same. I also updated the music
2-Castle: F.L.U.D.D. Tower (f.k.a. Seaside Castle)
This level was completely redesigned but it still mantains its core as a castle level where you have to use FLUDD while still having to avoid spikes, thwomps and ball'n'chains. The main difference is that the level now has a lot more verticality, specially in the second half, when compared to the old version which was pretty much a horizontal corridor all way through.
And that's really it, now it's time for World 3.