Here's my suggestions.
- Get a better avatar - Even though your avatar looks cool, I can't read the text, and it doesn't say much about your channel. I see it and think "Oh, this person must play a lot of slender", but then I look at your videos, and only see 1 maybe 2 slender videos. Make an avatar that represents your channel more, and make it easier read/see.
- Get a better banner - Like your avatar, it looks cool but doesn't do much for your channel. There is no channel name, schedule, saying, or any text at all. You want people to automatically know what your channel is about the second they click on it. Adding some images, and text can change the whole feel of a banner. I suggest adding your channel name, maybe a saying, or a schedule as well but that's optional. Maybe adding some images that represents the kind of videos you make. This may be my personal opinion, but I believe that channels look so much professional when the avatar & banner matches each other in some way.
- Get better Thumbnails - It looks like you have custom thumbnails enabled, which is great. However the thumbnails don't look very appealing. I can't even read the text in majority of them. Don't use font colors like blue, and pink over things that blend the colors together. You want to the text to stand out. For example, I can't read what the Ape Escape videos thumbnails say. I can see that they say "Let's Play Part 1,2,3,...", but that's after looking at it. You should be able to scroll through and easily see what the thumbnails are. Try to keep your thumbnails consistent throughout your series. Try to keep the same font, font color, and font placement throughout your videos. This will make it more professional looking, and more appealing.
- Your commentary seems pretty good, so I suggest Becoming active in communities. The more active you become on forums, and with other YouTube friends, the more it will help out your channel. Since you're already here on YTTalk, try to make friends with other people around the site, and be active on their channels. I'm sure they will return the favor. Plus there are a lot of gamers on YTTalk, so i'm sure you could find somebody
Maybe do collabs. That is a great way to grow your channel/audience.
I believe your channel is great, it just needs improvement on the visual side. Your commentary is good, but when you look at the branding of your channel, it looses it for me. Branding is just as important as the videos itself. You want people to click on your channel, and think "Hmm, this looks nice. Maybe i'll look at some of their videos". Because trust me, people are more willing to look at more videos if the visuals look good.