I started Icar when I was 14. It was all about zombies, then robots and destroying stuff. Most of the setting has matured with me (and the players, who have got older but arguably not matured) and other bits I've warped from their original intention because, well, I was 14.
I'm now working on a giant city-smashing machine called the Mk 8. When I was a young 'un, the Mk 8 was the pinacle of the arms race. One of these killer-rabbits showed up and it was time for the players to retreat. They were feared. I could make blood drain from the player's faces by the time I said "Mark ei...".
The problem is that it's not very elegant. Neither am I, to be fair, but I am not sure how it fits anymore. I've been through the drawings from when I was a teen and there are a bunch of stompy-looking robots that are either scaled up ED-209s or some sort of Manga-esque mech. Do I really need the stompyness? Probably but I do feel that of all the ideas I had, this one is having the most difficulty aging gracefully.
Are there any ideas you're living with, either in games or in games worlds that are a reflection of a much younger self?