Hello no you aren't too old. If you think you are too old for video games then you were too old for movies a long time ago. Video games are the cutting edge entertainment of our generation, and it's becoming a bigger industry world wide each year!
When I was 16 and played SC1, the APM was between 250-280. But now I'm 27, the APM is only 120. When you grow up, your speed and reflex will be slower. But that won't make me stop gaming. I'd prefer to play RPG and ARPG now. Maybe you won't have so much time to play games, but you can still keep a heart of gamer.
No, I'm hitting 25 this 22th of July and I can't wait for Skyrim in november (counting days).
But yes, I'm that kind of gamer who play for hobby and not for simple fun, try to play something different from FPS or RTS wich are competitive shit, try to play something like an interactive film, open world RPG and much, MUCH more single players.
You must find in games something that satisfy you, a good story, charismatic characters, you should achieve an emotive experience with games, not a simple "lol I pwned you".
I still play WoW, because I find myself VERY similar in a Belf Paladin, in the whole lore of belf and paladins.. and this let me to space and feel free with my character making special every single swing of sword
Apart that, of course, I have a life, a work, a girlfriend (who play WoW with me), and I'm always out of home doing shits with friends, so when I'll come back home I don't feel "old" playing a game, it's like watching a film and having homefun
One of my friends here on campus defended her PhD thesis earlier in the year and is likely to be a doctor very soon. I still see her playing pokemon on the benches outside the lecture halls. You never get "too old" for anything really. Your tastes may change over time, but it rarely has much to do with age. Do what you enjoy, and if it happens that it's no longer games, then find something new you enjoy.