SomeGuyDude
Just some guy, dude.
Yeah, it kinda does sound like a muddled mess. I don't mean that to be critical -- I honestly wanna help ya here.
Here's the thing: if you can't clearly and succinctly answer those questions for yourself, your audience will never be able to figure it out either. You have to talk specifically to that target audience and address them as such so they feel like you're talking exactly to them. If you don't make someone feel like you're talking to them, you won't make anyone feel like you're talking to them.
You also have to be able to communicate why your videos matter because few people will make the time investment to dig around on your channel to figure it out for themselves. If your channel doesn't matter to them, they don't subscribe, they don't watch, they don't comment. They just leave in search of videos that are valuable to them.
Per your answers, you definitely need to be more specific. You mention their interests, but dig a level deeper. Why do they care about these interests in the first place? What compels them to want to watch videos about older games and indie games in the first place? What's their motivation for going to YouTube and looking for these types of videos? You need to understand that and address it in your videos so when they find your videos, they stick around.
For example, a finance channel about getting out of debt isn't actually about money -- it's about hope. Disney Parks' isn't about roller coasters -- it's about giving families shared experiences together. Beauty channels aren't about makeup -- they're about confidence. Your gaming channel isn't actually about videos games -- it's about _______? (Making insecure adults feel like they're valuable when they win a game? Giving people with mundane lives the chance to feel powerful and in control? Providing expert knowledge that makes people feel socially respected when talking about a game with friends? Etc.) Why do your videos matter to your specific target audience?
You gotta nail the answer to that question, be passionate about it, and integrate it into your entire channel in every way.
Hope that helps!
The only issue here I see is that we're talking about a very specific kind of channel versus one that isn't. You mention a finance channel about getting out of debt. That is a very targeted channel. It has a goal in mind and all videos are going to be centered around this primary idea. Someone watches a YouTube channel on debt relief because there is a rather discrete need in mind that this channel will fulfill.
I don't think LP channels work on that same level. It really is about the people, and the intangibles of that person and enjoying their personality, their magnetism, their company. You see guys like Markiplier and JackSepticEye, IHasCupQuake or the Game Grumps. People don't stick around because they're seeking out answers or that they're targeting needs. They stick around because they (for lack of a better term) fall in love with the people making the videos. It's like you're visiting them, hanging out with them.
Maybe that's it. The "it's about ______?" question is that it's about the connection and intimacy with the audience. You watch the videos not because they teach you something or offer you some grand aid to your life, but... because you want to see them. I've seen comments on those big channels that said they were suicidal, depressed or otherwise in a dark place but those daily videos helped them find life again and thank you Danny/Arin/Jack/Mark for making me feel like I wasn't alone (not speaking personally).
You're obviously a very, very good mind for YouTube marketing and audience targeting, so PLEASE don't interpret this like my dumb little 100-sub self is arguing with your ability and methods. And you're probably right that there is a need to focus on what exactly a Lets Play channel offers and focusing on maximizing that. I just feel like these are quite different animals than scripted and "carefully produced" content done with active targeting of a need in mind.
Thank you very much for answering!