Going on 35, married and finishing up my PhD, but my wife plays games more than I do since she has a more 9-5 type job. So my situation is a bit different from a lot of people my age; however, there are a ton of ways my gaming habits have changed or are kind of restricted by age/career/or just plain ol' time restrictions.
I avoid MMORPGs, even if they do sound interesting. I don't have the kind of time commitment or money to invest in paying a monthly fee for one game. I also dislike the social aspect of these type of games, so basically avoid them.
I feel aged out or like I don't have the patience for games like Minecraft or Pokemon. Though with the latter its more like "there are only 151 pokemon and ain't nobody got time for more".
I avoid most multiplayer based games. I did play Destiny with a colleague, but he was way farther than me by the time I checked in and I never did end up doing most of the raids. I did enjoy all non-raid single player content in the main game and expansions though. Again, I don't care for social-aspects of gaming.
Easy mode, all day erry day!
Bigger backlog: More money + Less Time = Buying way more games, but way less time to play them.
I have no problem with big games (contradictory to my pokemon and minecraft comments), it's just that I have to put a self-imposed cap on them. For example, I've been playing skyrim recently, but once I hit hour 60 I'm putting it down.
Other big games I restrict to handhelds, where I can play them in bed, or sneak an hour or two in while in my office. For example, Dragon Quest XI in a few days, I pre-ordered the 3DS version, so I can play during my free time and have a chance to do everything possible in the game (but that's mostly something I do with every DQ game).