@jamesa-blackwell-57b383d3

The simplest solution is indeed using the viewport:

Make the canvas size much larger than the view port Draw a large backdrop in the stage canvas Lock the viewport on the key sprite
 

5b9cc078-5ca0-4999-ba1c-c55453084d13-image.png

 
Here is an example:

play.creaticode.com/projects/6842f3d73d952dd83a741d13

 
If this “does not work”, can you please explain what the problems are? We can either refine this or discuss a completely different solution.