Because a fullscreen of tiles takes a lot of bandwidth from the CD unit (and transfer time to the VDP as well). The CD bandwidth is the bottleneck, so you start to see the frame rate go down/get choppier. Something has to give and pace of the video/stream is more important than the number of frames in a unit of time.I also always wondered why the framerate of the earth level was so low, if it was pre-rendered why wouldn't they have just rendered all the frames.
It's already been known that Silpheed uses streaming for the background in game(you can crack open the files in the ISO and see the compressed video - albeit all messed up). Why would they do anything different for the intro? FMV, animation, streaming video - it's all the same thing.I just watched Silpheed's intro scene a few dozen times and now I'm watching the first level entrance cutscene. I cannot see any evidence of this being video either. The aliasing from the ultra low resolution polygons makes the ships almost look like they could be made of voxels. The backgrounds in these scenes are definitely something the Genesis CPU could o on its own. They're just flat walls like in Flashback and Out of This World. Then in the game certain aspects look more like they could just be a rotating 2D background, perhaps with some frames of animation, as much as they could be FMV. Other elements look more like FMV, but could just be animated as well.
What? The Silpheed intro? I've never seen anything to indicate the Genesis CPU itself could render such an intro at that frame rate.The backgrounds in these scenes are definitely something the Genesis CPU could o on its own.