Rod - Can you show me what you mean?
1) Create a new document
2) Create a rounded rectangle and fill it with red.
3) Create another rounded rectangle layer - smaller rectangle, and fill with a foreground (White), to transparent gradient blend. Set the opacity to about 60%.
4) re another image (File>New) so it opens a new window.
5) Use the Maze preset in GMIC (Patterns>Maze), to create a square maze. Default values should work fine.
Black bg and white maze wall lines. Use this image example for reference.
6) Edit>Copy visible - Edit>Paste in first rectangle image as new layer.
7) Set the layer mode to screen. Set the opacity to 35% and Filters>Blur>Gaussian Blur about 11.
8) Turn off the white bg layer and do a new from visible.
9) Copy the new layer and go to Colors>Brightness and Contrast set to these values.
Now just delete all but the two top layers, and white bg layer.
Now use the Filters>Animation>Combine bg script. Delete the white bg layer.
Save as animated PNG or GIF image with these settings
here are both.