The red buttons at the entrance of heroes I can only get 2 red rocks on the buttons;
the entrance it gives you at the upper end of heroes doesnt lead anywhere that you can actually go to (though I assume this is where I'm not seeing something - but the fucking yellow blocks dont give a way through); and the mirror part is also locked out it seems after I did everything doable

The purple rocks in the heroes obviously dont do anything
In the promise I did the ONE thing you can do...

Also if I spam undo on the overworld - it's not gonna undo completed levels right?

It must be something with yellow blocks on the overworld but there's literally nothing you can even do there