Yeah, I was going to ask similar questions about the submissions...
Why 25 FPS? Why not 30, or any FPS? Any decent video editing software should be able to handle it all.
And why MPEG 1? That standard is about 20 years old now. And same thing as above, any decent video editing software should be able to handle any common codec that you throw at it.
I think the best would be to ask for videos in the best quality possible: a balance of resolution, smoothness, and codec quality. And with sound effects, but no music.
Just an outsider's opinion though, I don't have anything to submit, so take what I say with a grain of salt. I do want to see Construct continue to succeed and expand its user base though, so I'm trying to help.