Alternative to MovieTexture for Free version users

Good afternoon,

I was asked by my game designer to play a video behind our login/main menu screen. I know that free users cannot us the MovieTexture feature and am wondering what alternative is there to allow a decent fullscreen animated sequence to play in the backgroud.

I know the best solution is to have an actual 3d scene playing in the background. But our graphical designer insists on a video/sequence of images for what he wants to do.

Is it a feasable solution to have a full screen animated sprite for that? I'd say that the loadtimes and resources spent alone makes this a negattive even assuming the animation would play eficiently.

The other best option is to have a static background image with smaller part animated with sprites like the metal sheen on a weapon, some animated glows on wizard hands etc.

I'd really like your thoughts on possible solutions. Thank you.