1. Channel About Page is well optimized. Great.
2. Video uploading frequency is great but, you need to research present market. Means, which people or gamers want to watch which type of videos. For that, just go to any popular gaming channels which has 30,000 to 50,000 subscribers. How they are getting traffic. Also, pick 5 to 10 channel and daily do R&D on that channel content and traffic. So, you can get idea about which content you should start producing.
3. For now, just do SEO work & put interesting content.
For now, That's it.