You can also use multiple tilemaps as layers. So using Terraria as an example, have a background image to represent whats behond the earth. Then have a tilemap that has solid objects with an extra layer below that for pickable objects, and maybe another tilemap that has jump-thru. You can quite quickly build complex interactive levels this way.
Thats a great idea actually !
@Vuuv I was thinking about something like RPG Maker, but now I got how it works !
Thank you !