no.. i think animation is always there but normally they're either having opacity 0 or positioned behind the gameboot (i think) so that you can't see them.
although there are a few exception that i encountered :
- on stratos theme which is based on 3rd birthday, bg animation stays in front of gameboot, fading away smoothly until completely gone,, the process takes around 1-2 seconds. i really don't know how this thing happens,,already edited a lot but couldn't change this.
- on sony mmod, wave (on wallpaper mode) stays on top of gameboot until the end. this can be changed by repositioning wave script at object tree if I recall correctly. i can't show you the exact lines since i don't have the data and tools right now though

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i don't know,,, maybe something like this


you can add glow effect,, changing the color between white to something more rainbow for bias effect,, rotating the lines etc....
to be honest I'm not really good in handling environment effect lol.. but i know it appears sometimes in some movies so you can watch them for reference