Well I had begun by making the odd boxes transparent but stars and galactic clouds prevented from playing the game fully, because I was unable to see some pencil marks. That is why I decided to make boxes opaque. But indeed, I hadn't thought to make only one sort of boxes transparent. I am going to try your modification, which must be better.
As far as the animation files are concerned, I simply use "Microsoft GIF Animator", which is free and pretty easy to use. Nevertheless, you have to convert images one by one to gif files, which allow less colors than other types of file. The best software I found to convert pictures to gif files with the best quality is "Microsoft Picture Manager", which is included in the "Microsoft Office Pack".
Damned, to much publicity for Microsf......
