Here is a hack I'm currently working on, Super Mario World - Some Random Adventure. I think this needs a new name lol. It is a vanilla hack but with custom palletes used, some ASM patches from the patches section (mostly fixes), and custom music.
Yoshi's Island Submap
Main OW Map
This world almost doesn't feature the use of custom palletes except for Yoshi's Island 4, which uses a custom pallete as it is a beach-styled level.