* issues
* todo
-** images for buttons
-** background
-** shelf's logics
+** make a semi-transparent plane under the instantiable items
+** manage the physics of the to-be-instantiated with a ghost
+** instructions
+** main menu
+** implement the operations of the buttons
+** create one level per item, then levels with more items
+*** e.g. item1, item2, item1+2, item3, item1+2+3, ...
+** build pipeline
+** magnet
* waiting
** version 0.0.yymmdd
** do intro video with moviepy