Originally posted by Doug WalkerBowser's castle looks awkward because of the lava around it (lava in clouds). But maybe some custom graphics are needed to fix that and since this hack is pure vanilla then idk
This hack isn't really a 100% vanilla hack, because it has custom sprites, a custom block, and also the title logo was made with custom graphics.
Here's Sea Caverns Secret:

In this level you hit message blocks to drain the water to be able to progress, like in Blind Devil's VLDC11 level.

There was a Buzzy Beetle here, but it fell in the 1 tile pit.

I've drained the water in this screenshot.
World 4 is now complete, but I need to make bonus areas, and then the hack must be tested.
Also, there will be 3 versions of this hack, a version without custom music, a version with vanilla music and remixed versions of the vanilla music, and a version with ports and some original music, all unsampled.
Linktree