OH wow, wow wow, what a fantastic start to the games.
I love time travel fics and much as I usually like whoever to return to their original time I was really wanting Harry to stay from about half way in so I loved the ending. I especially love that the paradox sorted itself out.
I really liked how a lot of the outcomes of the timeline were somewhat similar to the canon ones - Severus spying, Peter being a traitor, Lily and James together and having a child close to the timeline. I also love your characterisation of James, you didn't try to make him a better person younger in his life. :D
I don't know if I sound like I'm full of squee about this, but I SO am.
Oh and older Harry being fucked on his desk by younger Severus *drool*