This reminds me very much of my own father, though he wasn't a gamer. Coming from an older generation, his great love was books, and I loved it when he gave me a beat up old book from the 1940s, told me he read it many times, and "thought I might find it interesting." Looking back, I know he too faced anxiety about sharing these important, secret parts of his past: "will my son find this as captivating and glorious as I did, or will he put it aside -- or worse, read it to keep my feelings from being hurt?"
As a now out-of-the-house "adult", I can say that sharing your past with your children is perhaps the most profound and meaningful way you have to connect with them as a father -- at least this was my experience. Sons especially, I think, really want that connection to their dads. It helps them understand who their father was, what he was like as a child.