True, they did elaborate on the gameplay mechanics in an update, but the initial video was pretty vague and the initial video is the only thing most potential backers will watch.
After reading the update, I have a better understanding of the gameplay but that only makes it seem worse. The hack 'n slash and RTS elements don't seem to be merged well. They're basically separate game modes entirely.
I think GPG would have been better off focusing either on the RTS or hack 'n slash parts of the game. If they had, potential backers would immediately understand how the game plays and the resulting game would likely be better.