I tried to create a project with zero sprites but moving objects in lists, and this is how far I got. It is perfect so far, at least for one black rectangle (a mark). However, a problem arises with multiple black rectangles. The bug is described below. By the way, the list is a 13x32 grid, if you would like to know.
When two or more marks are present in the same row, then trying to unmark the leftmost one will unmark all marks in that row. I do not know why it happens, and I even tried to debug it with one more variable, but it did not work. This bug might be useful though, for example making an animation which wipes off a pixel image on the display.
