Well, I was browsing through reddit, and I found a mockup of what if a beach tileset was in Super Mario Maker: Super Mario World's theme. So I asked my good friend Epic_Stuff if he can do a pallet swap, and he did, but he missed a few things, so I figured out how to do it and did it on my own.
Credits to MrStickventuresYT for the original pallet, Epic_stuff for the original pallet swap and the background, and NightYoshi370 for the pallet swap and the 3DS import.
3DS Download