The definition of video should not be the defining issue here, but a video is definitely not a slideshow. A timelapse is considered a video, but it has to be engaging for us to promote it.
As to "gameplay" or any kind of video you submit; the simple answer is that you need to own your submissions 100%, if there's even a single flag from our system about your content not belonging to you or possibly being claimed by a third party because you are using material that belongs to them, the video will immediately lose all monetization. Doesn't matter if you won the battles or not.
You can't win battles or make money on Rumble with content that is not 100% yours.