The video of it as a walkthrough IS THE GAME. You do not need to PLAY it to KNOW IT. If you watched a full walkthrough of VII you could easily tell if it was linear or if the story was bad or if it had a good battle system.
Are you suggesting to me that by playing it you are given amazing powers of understanding or new vision that your eyes would not otherwise have had? Do you realise how preposterous that sounds?
Reading reviews, reading from people who have played it and then watching a proper video walk through are the best ways to judge a game before buying, and when you do watch it, you can immediately see the following:
1 line map
battle
cutscene
long battle
1 line map
Auto attacks by AI, numbers flying all over, deliberately high HP bosses
And so on. The only thing you cannot tell from a walkthrough at present is how good the story is and that is only because it is in Japanese. I will wait until a walk through is released in English and from watching the first 3 hours I will know whether I even want to rent it....
Have a good look:
YouTube - Broadcast Yourself.
I chose that at random. if you watch it surely you will geta good idea about how the game works. I did.




