Well the mic quality is a bit bothersome to me, you can hear a slight hissing in the background which might turn some people off. As for the banner I would suggest making it a little less plain, maybe a little line that says when you post/favorite phrase. The thumbnail's shadow for the white text, like you did in the first episode, sticks out more than the other thumbnails without the shadow so I would suggest changing it back. Also Minecraft is a pretty good start but a lot of people play it so you might want to switch it up a bit with something else later on or maybe some Feed The Beast/Tekkit stuff. People like mods because it's cool and brings a new perspective to a game that everyone knows.
I'm not really an expert on balancing out audio on LPs but this video helps a lot. It's a good guide on how to balance out the audio of the game and your own audio.
*Edit* Also you should do a call to action, tell people to sub/like/comment/fav/share because they're more likely to do that if you inform them and maybe put an outro with a little subscribe button with all your social media links? The outro part isn't really necessary and I've seen a bunch of people do great gaming videos without it but it does help out quite a bit and will get you a bit of exposure. Sometimes it's good to leave the videos on a cliff hanger so they will be excited for the next video. Last but not least, if you have a specific goal in video, mention it so the viewers will anticipate something!
I know that my videos lag a little bit, especially the facecam, and I am going to try a different technique to record both without it lagging to much. 
