As for FX, look at Kubrick's 2001, released in 1968. Look at Star Wars, released nearly a decade later. It's a difference of degree, not kind.
Finally, to take up your genre point, I don't think Lucas so much created a new genre as transposed some old ones: westerns, samurai flicks, and Flash Gordon serials. Genres that had bad guys in black hats, a sword/gun slinging hero with a special code of ethics, a mercenary hired onto the side of righteousness who ridicules the morality of the hero but who ends up himself a partisan. Watch Kurasawa's "Hidden Fortress"; now imagine the fortress is . . . in space, and that the two bickering peasants are robotic. Hmmmm. Oh, and what was the Japanese word for the period samurai piece? Jidai, was it? That word sounds oddly familiar . . .