Tomorrow’s release of Mass Effect 3 isn’t just one of the videogame events of the year. It’s one of the pop-culture events of the year. And last week, fans of BioWare’s deeply immersive action role-playing space opera got a tantalizing early glimpse at what’s in store. In a cinematic three and a half minute trailer called “Take Back Earth,” we saw the Reapers, that ancient machine race that periodically awakens to destroy all organic life in the galaxy, finally make their conquest of Earth. That is, at least until that stubbly interstellar savior, Commander Shepard, returned to spearhead the bloody interstellar reconquista.