Both videos are pretty cool! Also, I discovered that you made a mistake in world counter, in the videos it said you're in World 3, but World 3 is beach themed. In case, you have to change world counter number from 3 to 6.
The music I remembered are:
-overworld - Super Mario Bros 3 Sky Theme
-Level 6-1 - Kirby's Dream Land 3 - Ripple Field 2
-Level 6-2 - Kirby's Dream Land 3 - Sand Canyon 1
The next level, level 6-3, is absolutely the bridge level.
-------------------- Believe what you want, not every sentence is true.
Haters will always be haters and try and make you blue.
But blue is a pretty color, it doesn't have to end.
Even if the hate, is hidden within your "Friends".
This entire thing is beautiful, so I wanna see a sneaky peak of one of the fire levels in World 7 as I haven't really seen a good ol' volcano level in a SMW hack (but then I don't look at many hacks).
Ice and Fire in the same world? I didn't know this was Sword and Shield Maze
im not clever
I just would save that beauty of a castle theme remix for either ghost houses or Bowser's Castle (if it's gonna be lengthy like the vanilla SMW one) and use a remix of the NSMB1 or (preferably) the NSMBW/NSMB2/NSMBU castle theme. Personal preference, it's 3spooky5urusualcastle in my humble opinion
Oh yeah, and with Buzzsaw Bridge (not looked at all the previews yet )... gotta love them autoscroll fg clouds
5-Fortress: Neat lighting effect. Personally, I would have used Layer 3 for the spotlight and 2 for the background, but either works.
5-6: You seem to have a miner problem with that. The looks pretty engaging, and I quite like the background palette.
5-7: Now there's a custom sprite I don't see often. I'm assuming the title is a Sonic reference? Some Layer 3 clouds in the background might not be a bad idea, but the level seems neat enough.
5-8: Huh, never seen that background in a nighttime level. The palette looks a little bit off, but I like the idea of the level.
5-Castle: I guess I already commented on the video. The bullet-firing Bowser statues seem like they shot be shooting them from slightly higher up.
6-1: Nice level. I like Super Koopas. Nice submaps for Worlds 6 and 7, too.
6-2: I like the idea of this one as well.
6-3: And this one.
6-A: And this one. The obstacle placement in this one in particular seems pretty good.
The background is grainy and has dithering unlike the other graphics so I don't think they fit each other. Also I think you might want to increase the contrast in the foreground graphics
Everything else looks neat though, I love 6-4. Great work!