I'm not near as old as a lot of people in this thread, but I still have old guy complaints about games these days. Why is everything so damn long? I've got a wife and baby; I can't dedicate 6 hours a day to video games. I just started the Witcher 3 and I'm reading all these stories about how it takes 100+ hours. Great! That means I might get to see the end of the story by spring! I realize it's petty to complain about getting a huge amount of content for less money than we used to pay for N64 cartridges, but still. At what point is it just complete overkill? And for God's sake, if you're going to lock me into a cutscene, do me a favor and give me an actual timer beforehand. Make one of the characters say it; "are you sure you're ready to proceed, Geralt? The journey should take us exactly 47 minutes and 19 seconds, and we'll have no opportunity to pause once we've begun." That's some pretty handy information to have if I'm enjoying a quick game before bed and I don't intend on staying up until midnight looking for a damn save point.
Online multiplayer has gotten annoying because there seems to be a push towards the competitive, and while that's awesome if you've got the time to dedicate to it, it's really off-putting if I might be called away at any moment for a number of reasons. Oh, the baby's fussing, guess I'll just forfeit this competitive match and get docked points in my reputation so I will no longer actually be able to join any games. I can't even play CS with my friends now because they're always running classic competitive and I can't ever set aside 45 minutes and KNOW I'll be without interruption. So it's casual multiplayer with random people screaming racial slurs that just remind me why I stopped paying for Xbox Live. Online multiplayer just makes me angry now; it reminds me of how bad I've become since I can no longer dedicate 20% of my waking hours to gaming.
All I really want from gaming is a working version of Tetris Attack playable on any device. Give me that, stick me in a corner, and I'll try not to disturb you with my peals of jubilant laughter.