Attached a image of what i think the selection panel might look like/ what options it might have
I was thinking that instead of limited to circles, it should be able to have cuboids and other shapes.
And instead of it being a delete command, it should be a select command. This allows greater flexibility to select objects so that you can delete them/explode them/or hide all of them/turn them to dust instead of just removal.
Also you should be able to add two selections and/or subtract from them, just like in paint.net and/or photoshop if you've used those programs.