For your channel art, which includes the profile picture, banner and thumbnails. All of them are quite good. The logo and banner are consistent with each other. What I would suggest though, is to add an outro, but again, that falls to personal preference.
Now you have uploaded 4 videos till now, 3 of which were AC Blackflag. When I do reviews for other channels and give feedback, I am always honest, and this is what I am going to do now. If you are uploading a walkthrough to a game, which is who knows how long old now. Probably not many people will be interested in it. Everything is developing quickly now, and a 1-year-old game, especially from a franchise like AC or BO or Call of Duty, is quickly forgotten. If you want to upload walkthroughs, then you have to do so to newer games. Keep in mind that walkthrough channels are all over Youtube and that just reduces your chance even more.
However, if you think that you have what it takes to stand out in between all the other walkthrough channel. I would suggest sharing your channel with people you know. Your friends, family, relatives, people you see. The most powerful type of advertisement imo is the face to face or one to one advertisement. Reason is, you are facing that potential subscriber. You are able to convince him of your opinion and immediately, you can see his reaction. Is he impressed? Does he care?
So to conclude and precisely answer your question. To advertise your channel, I would suggest talking about it with friends and who you know. Is a walkthrough channel the best option for you out there? Maybe, but keep in mind that the challenge and competition is extremely high. That was it pretty much! What do you think of my feedback? Did it help? If it did, I would really appreciate it if you have a look by my channel and leave me feedback as well. Good luck!
