Six layers but I suppose it could be more and possible because the text is static with respect to the animation. If the text moved about it would be back to editing each layer.
Some general prerequisites for other animations. If the animation is optimised, unoptimise it and work in RGB mode.
Using 2 scripts / plugins
1. Combine background from the Animation section, see: http://chiselapp.com/user/saulgoode/repo...t-fu/index
2. The gimp_gmic_qt plugin from here: http://www.gmic.eu
and it goes like this, duration 3 minutes: https://youtu.be/NII1esx5QKA
Some general prerequisites for other animations. If the animation is optimised, unoptimise it and work in RGB mode.
Using 2 scripts / plugins
1. Combine background from the Animation section, see: http://chiselapp.com/user/saulgoode/repo...t-fu/index
2. The gimp_gmic_qt plugin from here: http://www.gmic.eu
and it goes like this, duration 3 minutes: https://youtu.be/NII1esx5QKA