To be fair, I've only played a handful of these, but I'm familiar with lots of titles even if I don't know crap about the game. I couldn't even tell you what type of gamer Killer 7 is. I just have heard the title and it came to mind.

My guess on 3C is that it's just something I've never heard of. Something to do with blackness/darkness and time or maybe afternoon. I can't imagine the significance of the specific time and I would've assigned significance to the numbers if not for the PM.