Yeah, I agree with Demon, I think that they will add achievements at some point in the near future because so many people (me included) love to hunt for them. It makes replaying old games far more fun - I always feel weirdly better and excited when I see an achievement pop-up.
Regarding the Fuzion Frenzy, isn't that a reallyyyyy old Xbox game that is multiplayer and has many mini-games? or perhaps I've confused it with another.... but I could swear I've played it at my friends like ten+ years ago. Interesting choice to add it on the backward compatibility. I think I'd prefer some of the newer Xbox 360 games that are still not on the list.