How do you get your Let's Play into YouTube Search?

I've made a few let's play videos and I started doing some searches for my own videos, when I search "Let's Play" and filter by most recent upload times I never find my upload. You'd think that by calling it "Let's Play (whatever - whatever)" and tagging it as such would yield a result when searched for upload time? Maybe I'm just not very aware of how the search system/tags work, but is there any good tips for getting your video's into search for a few new people looking to start building their audience?