@SwaggyXiao, please refer to my Scrolling Tutorial scenario on image scrolling (see main text and link at bottom on "Actor follow scrolling code"). The scenario is located at:
https://www.greenfoot.org/scenarios/18226
Scaling and re-scaling an image will usually distort and eventually "destroy" an image. Better would be to copy the image and scale it once; then go back and forth setting the appropriate image.
The background image must remain completely opaque. Using "clear()" on it makes it completely transparent, which is why you are getting trails and added residual images.
@Roshan123, iZip should be able to unzip them; although, I have no personal experience with iZip. You might need to re-suffix the file from ".gfar" to ".zip" for it to work -- possibly not.
@Roshaan123, oh yeah. Forgot about the lockout.
File menu was added so that the Options menu could actually work on something. Nothing more. I wanted to show what code would look like having a menu selection (in Options) actually doing something (operating on File menu).
2021/1/27
Benny's Tower Defense
2021/1/25
Scrolling SuperWorld
2021/1/14
Button Click Example
2021/1/3
Testing A Graphic Error
2020/11/30
menu class
2020/11/30
menu class
2020/11/30
menu class
2020/11/30
menu class
2020/11/29
Scrolling SuperWorld