With LMB you are able to pick and move sprite around the screen, when you release LMB sprite goes back to previous/original position.
When You press RMB on it, sprite is deleted and all others on the right side will jump/shift/slide/whatever to the left, to fill the gap.
First part and half of the second part of this behavior I managed to do without any problems. The problem on my side is that i cannot properly pick and move those sprites on the right.
I'm using few different sprites as one family with few variables.
Most important family variable is "sprite_index" which lets my position these sprites in a single row (from left 0 to 5).
Not using Array and any other thing.
Any help appreciated :)