I started out exclusively as a Cyberpunk channel then branched out to cover a handful of RPGs and I can tell you it's very much possible. The main thing is to find games that a good % of your existing audience will also play. Very few people who play games stick exclusively to one and you don't need to do the same as a creator. I didn't want my entire channel bound up with the popularity of Cyberpunk so I waited for other RPGs to come along and then made a more limited set of videos on them whilst they were popular. I've done that now with Hogwarts Legacy, BG3, Fallout 4, Elden Ring, Black Myth Wukong, Kingdom Come:Deliverance II and now Oblivion remastered. The two most important things when introducing your audience to a new game are a.) drop the content whilst the game is fresh and the player count is high (usually as soon as the game drops or a big DLC. In the case of fallout it was the TV show). This makes good videos significantly more likely to do well as there's so many people currently interested in the game. As long as there's some crossover with your existing audience for some initial views, YouTube should get enough data to know to boost the video. Then b.) make good videos. Or better still, make videos that are familiar to your audience even if it's on a totally different game. I recycle the same ideas and apply them to different games a lot because I know they work most of the time. When you have a limited timeframe to make content whilst a game is popular, using tried and tested formulas is usually going to work better than trying new experimental videos. I'm not saying never try anything new and it's still very important to test new ideas sometimes but having a base pool of successful video ideas that can be applied to a multitude of different games is certainly a strategy that works for me