The three reasons anybody play it are the puzzles, polish and setpieces. The combat is OK, the story is pretty dumb, there are way too many quick-time events (seriously, after about 30 over the course of a couple hours, I got tired of 'em quick).
And it's not a myth, it's a story cobbled together mostly from Hesiod's Theogeny, and borrowing things from Homer's Iliad, the Herculean myths, and a couple other 'side' myths.
I'm not gonna lie, I want to play GoW2 again, but it is definitely not for the story or combat.