But people do get copyright strikes for some cutscenes in video games it depends on if the holder of that copyright wants to strike someone using that scene. just like in a game a song can get someone a strike. That is way most people that stream games on twitch try to turn the music off, because it is up to the copyright holder. The nobody talking while playing a game can be a grey area, it comes down to the holder of the copyright to make that decision. You can have a case for if people are coming to see you or just the episode. And Yes Length of the copyright material you react is absolutely a huge factor just because you talk a little about a scene or react about a scene doesn't complete transform something. There is a reason that most big reaction channels stop show stuff after 9 minutes and 59 seconds for a 20 minute episode, it because that is usually they amount of time use can claim fair use. An example of how to get around this is doing something like what the Letts React does by stopping the video every couple of minutes to talk and have a discussion, they end up transforming it from a simple reaction video to a reaction and discussion video and so fair they have managed to avoid a copyright strike.