[djsumdog]

So long as the hosts of the video are commenting on the game, or making fun of it, or elaborating on the art in some meaningful way, that should fit the definition of fair use, shouldn't it?

If they're just playing through the game without comment, than maybe not so much? And then were do speed runs fit in?

Honestly companies should really embrace this. They get promotion on platforms like Twitch. Watching the game isn't the same as playing it, and it could encourage people to buy the game. I honestly only watch games I've played before, allowing me to examine the art and graphics without having to be involved in it again.

[Splines]

I think it really depends on the type of game being played. If you're playing a game like Gone Home (https://www.youtube.com/watch?v=Ak4wU8Gp2RQ), where there really aren't many (if any) decisions to make, you can watch the video and pretty much skip buying the game. On the other end of the spectrum are games like LoL or CS:GO where watching the game doesn't really replace playing it yourself.

I enjoy games from both ends of the spectrum, and the story-based games seem to struggle on the financials (from my perspective), and I would hate to see gaming culture evolve in a way that makes things harder for them to keep the lights on.

Consider this - on the extreme end it is the equivalent of someone streaming a movie while putting their face in the corner with their commentary. Would that be ok? (I could see a world where there's a technical solution that allows you to overlay a reaction video on top of your Netflix player. Maybe something similar could happen for video games.)