Cool! I think Let's Play channels can be a lot of fun. And that's cool if you guys are just trying to have fun. But, if you're trying to be serious about it… I'd have to say what I've seen from some of your videos; the humor gets a little flat. How much do you guys write before the video? That might be something you want to do. I know it can probably feel unnatural reading something that's pre-written or remembering it. But, trust me. A lot of comedy is pre-written and is then delivered in a way that feels natural and engages the audience. Try it out? If you haven't already.
Some awkward pauses here and there where I feel you're trying to find out what to say next. Avoid 'ums', 'likes', 'uhs', etc.
I wish you the best of luck!