I've made a lot of progress in this today

Just started working in the level settings in the editor, with what I've got so far, now the song of a level can be changed

I've added more objects

Now the background and ground colours can be changed

Some Geometry Dash: Legends screenshots I took.

Now there can be different pages of objects

Just fixed a problem with the fonts, it looks much better now, right?

Look at the thing that took me 3 hours to do (just the object selection systems, now it is made through arrays, it has animations and fixed a bug the previous prototype had)

That's how the editor looks so far, I will try to spend all day today adding objects, working in more keyboard shortcuts, implement pages and also, add a trigger editor

I did a little progress on the level settings