An overall okay expansion to d20 modern, but very limited in its scope. It basically tries to fill in all the details between the age of fantasy/myth that Dungeons and Dragons encompasses up to the d20 post WWII era. While it does that somewhat, it does so with a very narrow focus, that of continuing the 'shadow chasers' campaign from d20 modern through the 'past' era. Everything is pretty much glossed over, and there's only a handful of useful statistic information to allow Game Masters to expand the 'past' world on their own.
While not awful for what it is, if you're interested in 'past' eras, and role-playing in them, theres a lot of other d20 options available with a lot better treatment.
[3 of 5 Stars!]