i think yuo might be skipping a step with your channel. A lot of youtubers i've been watching for years started off making a variety of things like skits, animations, songs, vlogs, everything they could think of. after a while they got requests to to LPs and kind of evolved into a gaming channel. people who only do gaming right from the start do make it to 5,000,000 subscribers sometimes, but honestly, there's just too much competition.
if you make lets plays for fun without really caring about subs, that awesome, have fun!

but if you have certain goals regarding youtube 'success,' you've gotta do something to stand out of the crowd at first. are there any other types of videos you have considered making? any unique twists you could put on gaming???